The most valuable material in Mesoamerica

Jadeite is an unusual stone. It is both handy and beautiful. The stone is very dense and hard – as hard as steel. It is durable and tough – the stone does not break as easily as most other stones. And at the same time, polished jadeite can be gorgeous – in a bright, unusual color, slightly translucent and glossy. The best-known color of jadeite is deep green and, indeed, these are unusual and beautiful stones. Nevertheless, there are other colors as well. Ancient Chinese loved near-white jadeite, there are found beautiful lavender-colored stones. But one color stands out: there is a light blue and green-blue jadeite which was the most sought stone in the most ancient civilization in Mesoamerica – Olmec civilization. This culture flourished from 1500 BC to 400 BC and these people created truly surprising works of art.

Olmecs used diverse kinds of jade but since the 19th century art collectors noticed an unusual variety of stone – blue-colored jadeite, colored by traces of titanium and iron. This stone though becomes rarer in later, Maya art. Maya preferred deep green stones (Imperial Green) which are absolutely gorgeous but… more common.

Lost mines

Jadeite was the most valuable material for the ancient Olmecs, Maya, Zapotecs, and other Mesoamerican cultures.

In the 16th century whole of Mesoamerica was conquered by the Spanish. Mayans (who controlled the jadeite mines) dispatched guards to guard their treasure – mines of the most valuable material known to them.

Cortés and Montezuma were accustomed to playing a native game which in many ways resembles chess… It was their further custom at the close of each day’s game to present each other with some gift. At the close of one day’s game, the Aztec monarch presented Cortés with several large discs of gold and silver handsomely worked. Cortés was greatly pleased and so expressed himself. Montezuma smiled and said: The gift tomorrow shall be such that today’s gift will seem in value and preciousness, when compared with it, as no more than a single stone tile on the roadway… The royal treasurer of Montezuma brought in on a golden slaver the royal gift, four small carved jade beads. The bitter disappointment of Cortés was so great that he could scarcely conceal it.” (Willard T.A., The City of the Sacred Well. 1926).

But Europeans had quite different priorities: gold and better-known jewels, above all: emeralds. Thus Mayans kept their mines secret and Spaniards disregarded this. Guards of the mines died out, the location of the mines was forgotten.

When Europeans later found the beautiful jadeite artifacts of Mayans and other local cultures, they did not have any knowledge about the source of this stone. There were not known finds of jadeite in this region and some scientists even considered that jadeite was imported here from China. A closer chemical and structural analysis seemed to testify: the Olmec blue jadeite is different and, most likely, comes from another place. More careful geologists though noted that the conditions during the formation of rocks can be very diverse even in a smaller area.

Rediscovery of the Olmec blue jadeite

The finds of jadeite in the Central Motagua Valley are known to modern people since 1952 (Robert Leslie). Initially, the finds were negligible, and only in 1998, after the hurricane Mitch, the jade was rediscovered in the flood-disturbed river sediments in Motagua and its tributaries.

Until the early 21st century most of the jade mines were to the north from Motagua River, in the southern part of Sierra de Las Minas mountains. A great find was made near Rio Hondo town – prospectors found here high-quality jadeite in translucent, deep green color. Here also were found remnants of mining from the times of Mayan civilization.

In 1999 prospectors noticed the much sought blue jadeite in the river sediments. In 2000 Russel Seitz, led by local prospector Carlos Gonzalez, found the first (in modern times) mine of bluish jadeite near El Ciprés, north from Motagua River.

Already in 1995 there were noticed pebbles of bluish-green jadeite in the Río El Tambor, south from the Motagua River. Nevertheless, only in 2002 by Carlos Gonzalez were found the ancient mines with huge blocks of high-quality Olmec blue jadeite in the upper reaches of Río El Tambor. Some of the best finds have been made in Quebrada Seca. Especially impressive here is a boulder of pure jadeite which is some 300 tons heavy.

This find was further reported to the scientific community by K.Taube in 2005, who found several ancient settlements of the miners around these mines.

There are reported also other finds, further south – but, most likely, some of these finds are kept in secret.

Jadeite industry

Currently, the jadeite industry of Guatemala is centered around the city of Antigua, where the stones are carved and sold. Jadeite is mined in diverse locations which are up to 40 kilometers far from each other. For the most part, the mining is unsophisticated – a group of people comes with a truck, drive as close to the stones as possible, use gasoline-powered jackhammers to divide it in manageable chunks, load the pieces in the truck and drive to Antigua or some other location where they can sell this material.

Jadeite today still is not as valuable, as it was in the times of ancient Olmecs. It is also hard to evaluate the real value of these stones – the quality varies from piece to piece and much of the value is created by the skills and imagination of the stone carver.

The best samples of jadeite though are very, very expensive, with a price exceeding 600,000 USD per kg. Besides the “Olmec Blue” there are known and traded some more varieties of blue-colored jadeite from Guatemala: “Midnight Blue” (darker, more intense blue color) and “Ventana Blue” (lighter, more translucent blue). All of these varieties are extremely rare or, let’s say it directly: unique.

References

1. Karl Taube, Zachary Hruby and Luis Romero. Jadeite Sources and Ancient Workshops: Archaeological Reconnaissance in the Upper Río El Tambor, Guatemala, FAMSI © 2005. Page accessed on 18th June 2019.
2. David Hargett. Jadeite of Guatemala: A Contemporary View, Gems & Gemology, Summer 1990. Page accessed on 21st June 2019.
3. Kim Be Howard, A.G. Jadeite. Page accessed on 21st June 2019.

Find of Olmec blue jadeite of Río El Tambor is included in the following article:

History

The picturesque hills between An Phú and Lục Yên villages in Northern Vietnam hid their wealth of gemstones quite well. Only in 1983 here were discovered fine rubies and around 1987 – spinels as well.

This was the first big find of gemstones in Vietnam. The state-organized cooperation with Thailand in order to learn the mining, processing, and marketing of the newly found wealth.

Large-scale mining ended here around 1994 because the terrain here is complicated and the finds are scattered.

Now the mining is continued by small companies and individual people. For the most part, the work is done by groups of local farmers with their families and friends between the rice farming seasons. Most of the mining is done in alluvial deposits and also in the marble bedrock. Some finds though are inside the natural caves and some are even in rice paddies.

Unusual, neon-blue spinels were discovered here in the early 2000ies and since then this is the best-known find of these gorgeous stones in the world. Occasional spinels of this rare color have been found in Sri Lanka, Madagascar, and Pakistan. Promising is a find (late 2018) in Canada (Baffin Island), as well as beautiful and comparatively stones that are found some 20 km southeast of Mahenge in Tanzania (autumn 2021).

Gemstones of Lục Yên

In the hills are mined rubies, sapphires, spinels, and other valuable stones – occasional tourmaline, nice pieces of feldspar. Recently have been found also yellow danburite crystals.

The best local places to buy the stones are Yên Thế market, An Phu Old Market, Lục Yên markets, and some more markets around the mines.

Spinels of Lục Yên are among the best ones in the world – here often are found intact octahedral crystals. Spinel comes here in the traditional pink and red colors, there happen also interesting sky-blue spinels that change their color to lavender under artificial light. Beautiful are also bright, vivid pink spinels that seem to be glowing.

The most famous find though is a very rare, neon-blue spinel.

The cobalt blue spinel

Local gemstones are mined mainly from An Phu Formation – a nice, white marble that formed in the Upper Proterozoic and Lower Cambrian. This marble has been intruded by granite and pegmatite dikes, it includes also layers of amphibolites. The layer of marble, which bears the spinels, is more than 500 m thick.

While in some lenses of the white marble are found pink and red spinels, in some others have been found the rare blue ones. Research shows that this pure blue color is created by cobalt and also iron. Iron though does not play the main role – it seems, this element makes the hue more grey. Also, if there is too much cobalt, the stone is dark.

The best find of cobalt spinels has been Bai Son mine, where initially (around 2010) the stones were mined from the marble but now – from the gravel and mud around the marble cliffs. Here the stones are up to 5 carats large and have a glowing, bright blue color. Nice stones have been found also in the rice paddies north of An Phú and in some more places.

The value of spinels in the international market is increasing over the last years – and, why not? This is absolutely noble gemstone with similar qualities to the best rubies, sapphires, and emeralds. Cobalt blue spinel could be the most expensive variety.

It is also very hard to fake the color – it comes naturally and even a heat treatment is not needed. Since 2015 has been noticed a technology to color greyish spinels in vivid blue color with so-called cobalt diffusion treatment. An experienced gemologist can tell the difference rather easily.

References

1. Le Thi Thu Huong, Tobias Haeger, The-Long Phan. Between Rice Paddies and Karst Pinnacles. The Luc Yen Gemstone Mining Area, Vietnam Journal of Earth Sciences, 40(1), 47-55, Doi:10.15625/0866-7187/40/1/10915. Page accessed on 16th June 2019.
2. Adrien Trivier. Study of impurity in blue spinel from the Luc Yen mining area, Yen Bai province, Vietnam, InColor, Vol.2 2018 (Issue 39). Page accessed on 16th June 2019.
3. Boris Chauviré, Benjamin Rondeau, Emmanuel Fritsch, Phillipe Ressigeac, and Jean-Luc Devidal. Blue Spinel from the Luc Yen District of Vietnam, Gems & Gemology, Spring 2015, Vol. 51, No. 1. Page accessed on 16th June 2019.

The finds of cobalt spinels in Lục Yên are included in the following article:

The legendary Persian turquoise

Turquoise was one of the world’s first gemstones. The world’s oldest gem mines were developed before the times of Ancient Egypt, in the southern part of the Sinai peninsula around 6000 BC.

Persian turquoise mines have a similar age. Mining of the eye-catching blue stone started here some 5000 years ago – or even 7000 years ago! While the best Egyptian stones were exhausted and have much lower quality now, the mines near Nishapur are active up to this day. Even more – geologists have assessed that with the current tempo the mining can continue here for 200 more years!

For several thousand years the mine in Nishapur was the main supplier of this gem in the Old World.

Over these millennia turquoise from Nishapur has left a profound influence on the art and cultural values of Persia. People learned to imitate the sky-blue stone with glass, enamel, colors. Domes of the palaces and mosques, tiles in basins, garments, and jewelry were covered with diverse materials in turquoise color.

Turkish stone

When Persian turquoise was imported to Europe in the 17th century, it was supplied through Turkey. French named the stones simply “turquois” – “Turkish”. Thus the Europeans (and Americans and many others) now call the stone in the name of a country that has rather little to do with turquoise.

If Persians were obsessed with turquoise, Europeans were too. Stones of very high quality were not much cheaper than brilliants or emeralds, especially during the Napoleonic times.

Nowadays the market is flooded with turquoise of rather low quality, there are lots of imitations as well. Most people have never seen a high-quality turquoise – it is rare. But it exists, and the best one still is mined in the old mines near Nishapur.

Ma’dan – mining village

The stones are found in weathered trachyte from the Eocene period on contact with limonite and sandstone.

As it is usual, at first people gathered stones on the ground. When the blue stones in the scree ended, they dug into the cliffs. The Ali-Mersai mountain was favorable – veins of the stone were everywhere. Over the last centuries, the mountain has been crisscrossed by mines, and villages of miners have grown right at the entrance of the mines. The best-known mine is in a village named simply “the Mine” – Ma’dan.

Some of the best local mines are:

• Khak Ghermez – here are found stones of mild blue color without inclusions. The whole stone has the same color.
• Abo Ishaghi or Abdo Al’Razaqi – exhausted mine where the highest quality stones were found.

Every year some 30 – 40 tons of stones are mined in this area, some 15 – 20 percent are cut into gems. Unfortunately, mining has not brought much prosperity to the people. As with any mining, this is hard and often hazardous work, which up to this day is continued with rather primitive methods.

Processing and marketing

Most of the mined turquoise is further processed in three nearby towns – Firoozeh, Nishapur, and Mashhad. This is a fairly important business for the local economy with thousands of people involved. Most of the stones are exported to the Gulf Countries and East Asia.

The Persian turquoise traditionally is classified into three quality groups:

• Anqushtari (Angusthari) – the highest quality, with a rich blue color.
• Barkhaneh – somewhat less quality, with more markings and matrix.
• Arabi – stones with pale blue or green shade, with ugly speckles.

A turquoise of high value has an intense blue color – the darker the better. It is smooth and does not have inclusions.

One of the most sought varieties is the “Sleeping Beauty Turquoise” with absolutely flawless coloration. The Persian “Sleeping Beauty” should not be confused with the American “Sleeping Beauty Turquoise” from Arizona – which also is a high-quality stone.

References:

1. Turquoise Mine in Neyshabur, Iran, Paywand. Page accessed on 27th May 2019.
2. The Turquoise Guide. Page accessed on 27th May 2019.

The turquoise mines near Nishapur are included in the following list:

History and legends

Around 1879 – 1882 it became known that in Kashmir have been found sapphires of exceptional quality. According to traders, these stones were found high in the mountains in a place of a recent landslide.

Legends of Kashmir sapphire mines

Some tell that a local hunter at first found a piece of sapphire which was very handy to strike a light for his pipe – better than pieces of quartz. After some time he sold this stone to a local gem trader.

Another story tells that a trader brought a bag with borax to sell in the market and a sapphire happened to fall out of the bag, on the street. A jeweler went by and picked it up and immediately saw into it a jewel of high value.

At first, locals and other gem hunters flocked to this site and many stones reached the market. Initially, the stones were sold at absurdly low prices. Gems were resold at higher and higher prices until they reached the markets in Calcutta and local tradespeople there bought the sapphires per equivalent of some USD 400 000.

When Maharaja of Kashmir learned about this, he went mad and required that all the transactions need to be undone. Thus all these deals had to be redone backward: traders in Calcutta returned the stones per USD 400 000 to their sellers and so forth until the stones reached the initial market where some packs of salt were returned to the initial trader. And sapphires came to the treasury of Maharaja.

The whereabouts of the mine were unknown to most. Gem hunters went to several places in the mountains and most of these places did not bring any yield. Occasional sapphires were found in several places but in most cases, further searches did not bring any result.

There was only one place where the wonderful stones were found.

History

In early 1882 F.R.Mallet published the news about this find and first examination of the stones in a scientific paper – he proved that this stone is a sapphire.

The fabulous stones were mined for several years simply by looking in the debris of the landslide and turning around the upper stones. The finds were exceptional – the sapphires of the first years have been the best so far. The largest stones of gem quality were 12.7 by 7.62 cm large. But soon the number of gems started to decrease and Kashmiri authorities decided that science could help at this.

In 1887 there was made geological research of the mine. The report by LaTouche T.H.D. is the best source of the information about the mine up to this day.

Around 1905 the official mining ended but private prospectors continued to look through the rocks in the hope to find larger pieces of sapphire.

In 1906 – 1911 there was mined the “New Mine” some hundred meters from the “Old” one – some successful finds were made but this mine was much less valuable. Nevertheless, mining on both mines continued up to 1979. Since then the mines have been abandoned.

Often the mining was burdened by gangs that appeared unexpectedly and took away all the stones. In the 1940ies there was built a police outpost to guard the order in the mines – it has burned down and disappeared since then. Now the police are guarding the entrance in the valley in Padder.

Most of the best blue sapphire was kept in the Kashmir State Treasury. Some Europeans have seen these immense riches in the 1930ies: the largest gem was larger than a croquet ball (diameter – 9 – 10 cm). Rich traders wanted to buy some of these stones but were refused. There is no information about the fate of these stones since the early 1980ies.

Today it is practically impossible to buy a top-quality Kashmir sapphire. The value of the remaining stones is unknown – but very high and increasing.

The inhospitable Kashmir sapphire mines

It has been noted that local people have been quite good at gem prospecting for many centuries if not millennia. The late discovery of Kasmir sapphires could be explained by climate change.

It seems glaciers covered the area not too long ago – maybe up to the middle of the 19th century. As the giant ice shields receded, the land opened. And – as the land opened, it was prone to the weather and gravitational forces. Landslides happened and one of such landslides opened up a very special geological formation.

Local geology

In this place, actinolite – tremolite rocks long, long ago were permeated by granite, and on the border of both formations formed pegmatites. Pegmatites often contain the most interesting minerals. Here some unique local conditions without known analogs in the world created the most beautiful sapphires. There are some more places in vicinities where sapphires can be found – but the exceptional velvety blue sapphires were found only in a small area.

Several more interesting minerals are found in this area – garnets, black tourmaline, enclase, kyanite. Occasionally less experienced miners are fooled by lazulite – a bright blue mineral that is too soft for cut gems.

Work in the mines

The “Old Mine” is located above the tree level, in alpine meadows, and for the most part of the year, it is covered with snow.

Mining in the “Old Mine” was possible only for a few months per year – from the middle of July to late September. But, if compared to most of the gem mines elsewhere in the world, here the miners did not go deep in the ground – nearly all the stones were found in debris that formed from the landslide.

The very best and largest sapphires were found in the beginning, as the find was discovered. Sometimes the crystals were abundant – in some chunks of pegmatite sapphires were like “plums in a pudding”.

Some years later the finds became more and more scarce. Thus, during the season of 1888, there were found some 5 kg of gem-quality sapphires. Most of these sapphires were quite small. Soon after the miners started to look for gems elsewhere.

The best blue sapphire in the world

Some of the world’s best sapphires are found in another country – Sri Lanka, but, nevertheless, the sapphires of Kashmir “Old Mine” are unsurpassed: this is the best blue sapphire in the world. The sapphires which were found here in 1881 – 1887 are the best ones.

Just like many of the world’s best sapphires, Kashmiri sapphires have intense coloration in the outer part of the crystal while the middle part is less intense or even colorless. The color is intensified by heating and in these noble stones after the heat treatment, the color is stable. Often the wonderful blue gems are just a cut-out from the outer rim of larger crystals.

A characteristic feature of Kashmir sapphire is its velvety texture – the stone contains numerous small inclusions which cause slight haziness. At the same time, these crystals are lucid.

References

1. LaTouche T. H. D. The Sapphire Mines of Kashmir. Rec. Geol. Surv. India. 23, 59-69. Page accessed on 6th May 2019.
2. History Padder Valley. Page accessed on 6th May 2019.
3. Richard V. Gaines, The Sapphire Mines of Kashmir, doi.org/10.1080/00357529.1951.11768232. Page accessed on 6th May 2019.
4. Richard Hughes, India, excerpt from a book Ruby & Sapphire. Page accessed on 6th May 2019.

Kashmir sapphire mines are included in the following article:

But 100 years ago this was quite a different story – these stones were a trendy novelty, a kind of competitor to the famous emeralds.

Aquamarines of Minas Gerais

Beryls come in different colors. Most valuable beryls and some of the world’s most valuable gemstones are high-quality, deep-green emeralds, but similarly gorgeous are golden heliodors, red beryls from Utah, pink morganites, and other varieties. But aquamarine of diverse hues is the most beloved beryl after emeralds. Aquamarine is light blue beryl of diverse shades – for example, there are found marvelous blue-green or noble grey-blue, incredibly transparent stones.

Pegmatite dikes in Minas Gerais provide some of the world’s best beryls, especially aquamarines. People here have found gorgeous gems while digging wells, making roads, or digging the house foundations.

Story of Maxixe Mine

Around 1917 there was reported an unusual find: beryls in a deep blue color, similar to the color of the best sapphires. This discovery was made in a single locality of Minas Gerais state – Maxixe Mine, in alluvial gravel deposits, together with fine, pink tourmalines.

These stones became an international sensation overnight. Shipments of these wonderful stones went to jewelers of diverse countries and production of new, unusual jewelry started.

The blue color is caused by chromophore centers in the crystalline structure, caused by small amounts of anions, e.g. carbonate ions.

Researchers at first noticed the unusual pleochroism of these crystals. In one direction these crystals were deep blue, but as the stone was turned, it became nearly colorless.

But much worse news came soon after: one after another these beryls lost their beautiful color and turned into rather common, slightly yellowish, transparent stones.

It turned out that the color of Maxixe beryls is lost after a few days under direct sunlight or if heated. As a result, the demand for these stones dropped and jewelers had a painful loss.

Maxixe Mine was abandoned. It is even hard to find proper images of these beryls but stones from Maxixe Mine seem to be lost.

Occasional discoveries of similar blue beryls were made in some more places around Brazil and then also – in some more countries of the world. But these stones were not any different – their blue color did not hold.

Other finds of deep blue beryl

New maxixe beryls in a larger amount appeared on market much later, around 1973. Closer research showed that at least part of these stones was colored artificially, by radiation. There was the usual story – these stones also discolored under the heat or sunlight – but one could irradiate them and make them blue again.

Currently, there are sold maxixe crystals of diverse quality from several locations around the world: Nigeria (Jos Plateau), Nepal, Madagascar, Sri Lanka, and others. Similar stones have been reported also in Canada (Yukon).

References

1. Blue Beryl (Maxixe). Mindat.org, March 2006. Page accessed on 13 April 2019.
2. Ilaria Adamo, Alessandro Pavese, Loredana Prosperi, Valeria Diella, David Ajò, G. Diego Gatta, and Christopher P. Smith. Aquamarine, Maxixe-type Beryl, and Hydrothermal Synthetic Blue Beryl: Analysis and Identification. Gems & Gemology, Fall 2008. Page accessed on 15 April 2019.
3. Edna B. Anthony, Aquamarine: A Cyclosilicate. Page accessed on 15 April 2019.

Maxixe Mine is included in the following article:

Location of Sar-i Sang mines

Sar-i Sang mines are located in inhospitable Hindu Kush ranges, on the right bank of Kokcha River, a tributary of Amu Darya. The valley of the Kokcha River here is some 200 – 180 m wide, surrounded by up to 6 km tall mountains. This is a harsh highland, without vegetation, covered in snow for the most part of the year. Even in the summer, the nights here are frosty although on the days it can be quite hot. Miners have to ascend from the river up to 450 m high in the mountains and work in mines where the temperature is around 2° C.

Sar-i Sang mines are the last active mines of high-quality lapis lazuli – in the past nearby existed some more not too far from Sar-i Sang. Often these mines are called Ladjuar Medan, also Ladjuar Medam, Lajur Madan, Mahdani Lojward, and similar. This is simply “lapis lazuli mine” in local languages, e.g. Dari language. In Sar-i Sang are several separate mines, such as Madan Char, Pitwak Mine, and Darreh-Zu – former mine which has been exhausted and abandoned.

Geology

There is lazurite and there is lapis lazuli. The first – lazurite – is a mineral. This is a gorgeous, deep blue silicate mineral that sometimes (mostly in Sar-i Sang) can be found in crystals. The largest crystals are up to 5 cm large. This is not a gemstone – crystals are not transparent and mineral is not very hard. Lapis lazuli is a rock, which consists mainly of lazurite but there is present also calcite (white), pyrite (metallic yellow), and sodalite – another fine, blue mineral. In Sar-i Sang mines has been found one more beautiful blue stone – afghanite, which can be used as a gemstone.

Name “lazulī” – is the ancient Persian name for this stone, while “lapis” is Latin for “stone”.

Lapis lazuli comes in different shades and qualities and local miners and traders divide the lazurite of Sar-i Sang into three main grades (with their Persian names):

• Neeli (nili) – deep blue stones in indigo color, the most valuable lapis lazuli. Such lapis lazuli is found mainly in Sar-i Sang and only in very rare cases – elsewhere in the world.
• Asmani (assemani) – light blue stones. These stones have less value, but make no mistake – this is a gorgeous stone in a very intense blue color, frequently with white calcite veins.
• Suvsi (sabz) – blue-green variety. The least valuable variety, but still – a good ornamental stone.

Lapis lazuli has formed in skarns – limestones or dolostones which were modified by pressure and high temperature through geological processes. In Sar-i Sang these skarns are found in Archean gneiss and lapis lazuli here forms veins. The best veins are not too large: some 1 – 10 meters long.

Locals consider that the best stones were found nearer to the land surface and, of course, were mined and shipped away long ago. Nevertheless, the mountains here still keep lots of fine lapis lazuli.

Throughout millennia local people have searched through the mountains to find other mines of lapis lazuli – and we can consider that they have found all of them… or almost all. In the 1930ies Russian geologists, following the local legends, found one more find of good quality lapis lazuli some 100 km from Sar-i Sang, in Tajikistan, in Ladzhuar-Dara. Access to this find though requires brave heart and climbing equipment.

History of Sar-i Sang

Mountains could not hide the beautiful blue stones from the people – lapis lazuli is mined in Sar-i Sang (or was mined in nearby mines) since the Neolithic Age, the 7th millennium BC.

These stones were found in the Neolithic burials of Mehrgarh (around 7000 – 5500 BC) – the precursor of Indus Valley Civilisation and lapis lazuli was highly valued also in the times of Indus Valley Civilisation. Back in these times not too far from the mines developed a trade city – Shortugai, where one of the main trade items was this stone.

Blue stones were desired in any market – around the 4th millennium BC or earlier stones from Sar-i Sang reached Mesopotamia and were some of the most used decorative stones here. Around 3300 BC lapis lazuli reached also Ancient Egypt. This stone was used for the funeral mask of Tutankhamen (1341 – 1323 BC), Cleopatra used a powder of lapis lazuli as eyeshadow.

Lapis lazuli from Afghanistan reached even Mauritania in ancient times. This stone has been mentioned multiple times in the Old Testament as “sapphire”.

In medieval Europe, lapis lazuli was ground into a powder and used as the most expensive of all blue pigments – ultramarine. Lapis lazuli from Sar-i Sang in such form was used by Titian, Vermeer, and other great artists in their works of art. If you see the deep blue color of the clothing of the Virgin Mary in Renaissance paintings – there is a high probability that this is a small piece from the remote Hindu Kush mountains.

British explorer Captain John Wood reached the mines in 1838 and wrote: “If you do not wish to die, avoid the Valley of Kokcha”. He was a witness to the dire conditions for the miners in this area. Thousands of poor men came here all over the region and worked in this inhospitable valley.

Until the early 20th century miners made a fire under the rock – or in special holes made in the rock. When the rock was hot, they poured cold water on it. Cliffs fractured and then miners hammered the rock until they got the desired stones.

Of course, this exhausted any wood or anything else that could be combusted in the valley. The invention of explosives changed this business – now the stones are mined with explosions. This could improve the speed of work but the life of workers is not much easier – they work in primitive conditions and quite frequently die or get injured in accidents.

Even more frustrating is the division of wealth. Miners get paid only a small fraction of the real market value: most of the profit stays in other pockets. Unfortunately, peace in this region is a rare phenomenon and for long decades and even centuries unrest and war continue in the mountains of Afghanistan. Income from the gorgeous blue stone, unfortunately, is feeding this war. Also lately, around 2014, the profit was used to fund illegal armed groups. In order to cut this source of financing, mining has been almost stopped in Sar-i Sang for several years by the government.

References

1. Daniel Russell, Mining Lapis In The 19th Century: the narrative of Captain John Wood, explorer. Mindat.org, March 2006. Page accessed in the 5th March 2019.
2. Peter Bancroft, Lapis Lazuli from Afghanistan, excerpt from Gem and Crystal Treasures (1984) Western Enterprises/Mineralogical Record, Fallbrook, CA, 488 pp. Pala International. Page accessed in the 5th March 2019.

Sar-i Sang lapis lazuli mines is included in the following list:

History of Benitoite Gem Mine

The story of Benitoite Gem Mine started in 1907 with James M. Couch – a Californian rancher who decided to prospect in the Mount Diablo range with an aim to find copper or cinnabar. Once, after a few days of research near his campsite, James noticed an exposure with blue crystals. The ground below this exposure was covered with thousands of these blue crystals. Crystals had an intense blue color, they were transparent and glittering – there were no doubts that this is a valuable find. When he managed to go through a bush, James found even more – a small cave that was lined with thousands of these gorgeous crystals (this natural wonder, unfortunately, was dynamited later in an unsuccessful attempt to get the crystals). The excited miner gathered pockets full of these crystals and rushed to tell about his find.

It was not clear what kind of stone this is. It looked like sapphire, one jeweler considered this to be blue obsidian. The prospectors sent the samples to the University of California, Berkeley. Only here geologist George Louderback found out that this is a newly discovered mineral. He named it benitoite after the site of its find near the headwaters of the San Benito River.

Later James Couch was tricked out of the ownership of the Benitoite Gem Mine. The mine was worked by R. W. Dallas, who ordered to make a tunnel through the outcrop. In later years the owners of the mines changed, and many stones were taken also by the collectors and just people who liked to beautify their gardens with large chunks of unusual rocks.

For decades the mining was brutal and nearly all gems were lost in the process – pulverized and otherwise damaged. Only much later it was discovered that hydrochloric acid eats away other materials and intact crystals of benitoite can be obtained.

It is estimated that there are no commercially valuable veins of these crystals left (although no one knows this for sure) and in 2005 the mine was opened to the public. Now the visitors are purchasing fairly expensive tickets to enter the park. Nevertheless, large and beautiful crystals still are found here.

Benitoite is a state gemstone of California since 1985.

The bluest gemstone?

Benitoite is one of the very few gemstones in the world which has a naturally intense blue color – most of the others (e.g. tanzanite, sapphire) in most cases need heating to excel the color. Stones have a noble sapphire blue color, although there are also colorless and pink samples.

This stone has also quite an impressive index of refraction – it is one of the brightest, fieriest gemstones, surpassing diamonds in this respect.

This mineral forms beautiful crystals of a rare form with five points. Sometimes is found an even rarer star-shaped form with 6 points – there have been found approximately 24 pieces of such benitoite crystals.

Benitoite can be fairly easily identified by ultraviolet light – then it glows in a bright blue to white color.

The rarest and most expensive gemstone?

This stone is found in several places around the world but stones of gem quality are found only in one site in California – Benitoite Gem Mine. Some 7 – 8 km to the northwest is one more find – Junilla mine, but only a few specimens of gem quality have been found there. Elsewhere are found either very small crystals or just traces of this mineral.

It has been assessed that between 1907 and 2003 only some 10,000 carats of this gem have been cut and polished. Benitoite of high quality can be more expensive than diamonds, emeralds, or rubies – the price may exceed 10 000 USD per carat!

Together with benitoite are found other very rare minerals – neptunite (beautiful as well!), joaquinite-(Ce), and others.

Everyone can visit the mine and look for the gems himself – on weekends California State Gem Mine is open for visitors and people can search for the stones themselves – and, according to the site visitors, there is much fun and unexpected excitement.

References

1. Benitoite, mindat.org. Page accessed in the 29th January 2019.
2. George Davis Louderback, Benitoite, a New California Gem Mineral. University of California Publications, Bulletin of the Departments of Geology. Vol. 5. pp. 149-153. 1907. Page accessed in the 29th January 2019.
3. California State Gem Mine. Page accessed in the 29th January 2019.
4. The Benitoite Story: California’s State Gemstone. Page accessed in the 30th January 2019.
5. Benitoite Gem Mine, San Benito County, California. Page accessed in the 30th January 2019.

Benitoite Gem Mine are included in the following articles:

History

Maybe one day there will be made a series about tanzanite. An attempt at the scenario by Wondermondo:

The first episode: “False start”

In January 1967 young Maasai man Ndugu Jumanne Ngoma was going to visit his relatives in Kiteto village. As he crossed the low Merelani Hills, he noticed something unusual – blue, transparent gems. He was not in a hurry – thus he stopped and started to pick up these stones. Over the course of several hours, he collected some 5 kilograms of these natural wonders. The value of this find today would be at least one-two million US dollars.

When Ndugu reached Kiteto, his friends advised him to take a bus and go to Nairobi to sell the blue stones in the gem market. There he definitely will get better profit than in the nearby Arusha town.

Thus Ndugu borrowed some money and went to Nairobi. He found an office of gemstone dealers, went in, and showed the gems. “Leave them here, we will determine their value (if any) and will send an answer to you somewhat later” – said dealers, and the simple country boy agreed – just asked for some money to return home.

It seems, these dealers still are busy trying to find out the value of these stones, and Ndugu (if he is in good health) still is waiting for the message from Nairobi…

The second episode: “It begins”

In the same January 1967, another Maasai man Ali Juuyawatu noticed a cluster of deep blue crystals on the ridge of Merelani Hills. He told about this find to tailor and gold prospector, Portuguese Manuel d’Souza, or, as he was known among locals – Mad Manuel.

Mad Manuel picked up these stones – they definitely looked interesting, although it was not clear what kind of mineral it is and what could be its value. Stones looked like sapphires but had an unusually vibrant color.

Manuel showed the stones to geologist John Saul but the latter also could not determine them and decided to send the stones to his father, another geologist Hyman Saul in New York. Saul-elder brought stones across the street to the Gemological Institute of America and specialists there determined that this mineral is zoisite.

In the meantime, several more geologists in Tanzania received samples of this stone and their decision was the same – this is a very unusual variety of zoisite.

The third episode: “Tiffany”

International jewelry giant “Tiffany & Co” noticed these blue stones early. And they – gem cutters, designers, marketing specialists, and, of course, managers – acted fast. In 1968 consumers were introduced to a new, beautiful gemstone named “tanzanite” through a sophisticated marketing campaign.

In fact, geologists initially called the stone simply “blue zoisite”. Jewelers at Tiffany were not happy about this – after all, this sounds a bit like “blue suicide”. Try to sell something with such a name!

Meanwhile, the country of origin – Tanzania has a beautiful, tuneful name. Thus – tanzanite! The marketing campaign of Tiffany declared that this is the most beautiful gem discovered over the last 2,000 years, and stones were included in beautifully crafted rings, necklaces, and brooches. This definitely was a big success for “Tiffany & Co”, well-timed and well-executed. Tanzanite is one of the main gemstones in Tiffany’s jewelry up to this day.

The fourth episode: “Mad times in Merelani Hills”

People headed towards Merelani Hills. We have heard these stories – whether this is a gold rush in Alaska in the 19th century or the mining of diamonds in West Africa now, human nature stays the same. Thousands and thousands of people were digging through the cliffs and dust of Merelani Hills in 1967 – 1971. Everything of value disappeared from the surface of hills in some months’ time and people started to dig deeper in the ground for the next stones. They were disturbing each other, pits and shafts frequently collapsed, and most did not find anything and were increasingly irritated. Conflicts were commonplace, just as theft and heavier crime.

Tanzanian government interfered in 1971 (by that time some 2 million carats of gemstone were mined) and nationalized the mines. But this did not change much – the chaos in Merelani Hills continued. Sometimes up to 30 000 people were working side by side in this small plot of Tanzania and in total, some 70 000 people earn their income thanks to the tanzanite.

The fifth episode: “The big guys know it better”

In 1990 the find of tanzanite was divided into four blocks – A, B, C, and D, where the mining rights in B and D were given to local miners, but A and C – to large operators (now small miners are also in A block).

Since 2004 block C is operated by the company “TanzaniteOne Mining Limited” – a mining company that strives to be a showcase of ethical business. And, indeed, mines (up to 800 meters deep!) of this company are a lot more safe and comfortable than in the other sectors, workers are better protected socially, tanzanite stones are getting added value (sorting, cutting) in their home country – Tanzania.

In order to promote knowledge about the real value of tanzanite “TanzaniteOne” has created a subsidiary non-profit organization “The Tanzanite Foundation” which strives to improve the living conditions of the local community and, especially, workers in tanzanite mines. Nevertheless, local miners, which work outside the “TanzaniteOne” sector, consider that “The Tanzanite Foundation” is a typical case of astroturfing – an artificially created pseudo-civic organization that imitates socially important activities in order to retain the control of large companies over natural resources.

What about the other – sectors of local miners? Not much has changed except that mines are going deeper and deeper and work is harder and harder. One needs to descend hundreds of meters into narrow and dangerous ratholes and work through dust and cliffs in search of increasingly rare tanzanite crystals.

The mines are gradually exhausted. In 2011 “TanzaniteOne” mined some 2.5 million carats and earned 24 million USD. Since then the amount of tanzanite and profits are falling, and the number of workers is decreased. Mines go deeper and deeper and it is increasingly expensive to maintain them. Thus it is expected that around 2030 – 2040 the mining may stop here altogether.

Geology and chemistry

Zoisite

Tanzanite is a variety of a rather common mineral – zoisite.

Zoisite also can form beautiful, transparent crystals which are colorless, greenish, grey, or brown. Fine gems are cut from zoisite too – but the value of other varieties is not as high as the tanzanite value.

Blue zoisite of Merelani Hills

Only in one place on Earth is found zoisite in wonderful, deep blue color – this is in Merelani Hills, Tanzania (although some ink-blue gems of zoisite were found also in the Tsavo region, Kenya). This zoisite – tanzanite – is found in a small area that is just 7 by 2 km large. Tanzanite is at least 1000 times rarer than a diamond.

This gemstone has formed in metamorphic rocks and is mined together with several more beautiful gemstones, such as chrome diopside, tsavorite, blue apatite, grass-green tremolite, and another unique gemstone – axinite-(Mg). In Merelani Hills are found the most beautiful crystals of graphite in the world – one more highly valued collector’s item.

Mines in Merelani Hills have been very rich and the quality of mined jewels does not decrease up to this day. Thus, from 1995 to 2005 there were mined some 39 tons of tanzanite.

The largest rough piece of tanzanite was found in 2005. The weight of this stone was more than 3 kg: 16,839 carats. It was named “The Mawenzi” – after one of the summits of nearby Kilimanjaro.

Heat treatment for color

Rough tanzanite is reddish-brown to colorless and there is needed heat treatment to bring out the beautiful blue-violet color. There is needed heat of some 370 – 390 °C for some 30 minutes. The process is risky: if a crystal has some cracks, it shatters in the process.

Sometimes nature creates these blue crystals. Initially, in 1967 there were found beautiful blue crystals on the ground surface. These crystals, most likely, were heated by forest fires. But also deeper in the mines in some places crystals are blue – these pieces of zoisite, most likely, got heat from some geological processes in the past.

Tanzanite by far is not the only gemstone that is heated. For example, some 90% of sapphires, most of the amethysts, ruby, aquamarine, and, other stones are heated as well. Sapphires can be heated at much higher temperatures for weeks, totally transforming the stone.

Thus specialists do not consider the comparatively mild heating of tanzanite to be “cheating” – especially if this happens naturally as well.

Miraculous color effects

The unusual blue color is created by trace amounts of vanadium and/or chromium – similar as in the case of extremely rare blue garnets (see blue garnets of Bekily, Madagascar).

Tanzanite has a very unusual property – trichroism. This means that a crystal of tanzanite changes its color depending on the direction of how one looks. From one side it may be deep blue, from other – purple, and from another – burgundy. There happen to be other colors too: indigo, cyan, green, yellow.

In fluorescent light, the blue color is more intense, in incandescent light the violet hues are more pronounced.

After the heat treatment stone is dichroic – color changes between purple and indigo or blue. Heat treatment removes the brown – burgundy color.

Rarely the stone gets a set of green and blue color. Such stones have much less value as gems, but collectors love them – these stones are especially rare.

The most valuable – deep blue color – is only in 1% of tanzanite samples.

High value

Thus far there has not been noticed synthetic tanzanite or high-quality imitations. This again is rare – and increases the value of the stone even more: if something is sold as tanzanite, a client can be sure that this IS tanzanite.

The price of the highest valued tanzanites may reach 1200 USD per carat and it continues to increase. Tanzanite is also one of the highest valued stones for collectors – even in the largest collections tanzanite takes the central role. Many specialists consider that this is the noblest of all blue gemstones, surpassing even the centuries-long fame of sapphire.

References

1. Tanzanite Foundation. Page accessed in the 1st December 2018.
2. Working the Blueseam: The Tanzanite Mines of Merelani. Now this is a great website! Accessed in the 1st December 2018.

Merelani Hills are included in the following articles:

Garnets – colorful gemstones

Garnets are some of the most popular gemstones. These stones are hard, with gorgeous and lovely natural crystals and diverse, bright colors. Group of garnet minerals includes some 25 – 30 minerals with a very similar chemical structure – just the kind of metallic elements changes in the chemical formula. Some garnets include magnesium and aluminum (pyrope), some – calcium and chromium (uvarovite), etc.

Garnets come in all colors. Best known might be the deep red and purple pyropes and almandines, bright orange spessartine and light-green grossular, as well as emerald-colored demantoid (a type of andradite) and bright green uvarovite. Schorlomite is black, several types of garnets are rose-colored, brown, and yellow. Very rare is also colorless garnet (leuco garnet), a rare kind of grossular which can be found in Canada, Mexico, Tanzania, and Burma.

But on the jewelry market, there were not available blue garnets. Until 1997 – 1998.

Bekily blue garnets

Around 1997 there started mining of beautiful garnets north of Bekily, a poor and remote area in the southern part of Madagascar. Searching (and finding!) valuable gemstones is nothing new in Madagascar – this island is very rich with top-class gems and here have been found quite unusual gemstones, such as grandidierite.

At first, prospectors thought that they discovered gem-quality alexandrite – a very valuable color-changing gemstone. To their surprise, this was something even rarer – blue garnet.

Such unusual daylight color amazed gemmologists – blue garnets were something new to them. This was not one or two occasional stones – specialists back then obtained some 160 samples of these unique stones (1.).

Stones were obtained in the gemstone market in Bekily – the location of their find was not disclosed. Now there are rumors that the find has exhausted already in 1999 (2.) but the political and social unrest in the country could also be blamed for this. From time to time some color change garnets still come from these mines but clear blue ones are missing now and in the market can be seen the same stones from the late 1990ies which tend to become more and more expensive with each resale.

The unusual change of colors

These blue garnets are a mix between pyrope and spessartine, with small amounts of almandine and grossular contents. Their color-changing scheme is as follows: in normal daylight, they are blue (the rare best samples) or grayish-blue. In white light (e.g. from LED lamps) they are bright blue. In the usual artificial light, they become red – reddish-purple. Color change, most likely, is created by unusually high amounts of V₂O₃ (vanadium oxide) and some amount of chromium oxide.

Most of the “blue” garnets from Bekily are not really blue but rather grey-bluish, also green-blue. But there are some clear blue specimens. Even rarer are well-formed crystals of blue garnets – prospectors are finding just a shambles of crystals. But at least two crystals of pure blue garnets exist (3.).

Size and price

These stones were small – the largest gem-quality blue garnet in 1999 was just 9.5 carats large. Cut stones are much smaller – 0.1 – 0.8 carats.

Larger blue garnets with a color-change effect are very expensive, with a price exceeding USD 1,500 per carat. But for this high price garnets need to be large and pure blue without the gray or green color. Nevertheless, the more common alexandrite with similar properties could be more expensive.

Are Bekily blue garnets unique?

Color-change garnets from Sri Lanka (finds in Embilipitiya and Athiliwewa) and Tanzania (finds in Umba and Tunduru) have been known since 1979. This always has been a rarity, with some occasional bluish-greenish garnets among them.

Blue garnets, similar to Bekily blue garnets, have been reported in Kenya, Taita-Taveta County since 2009. Nevertheless, the unique stones from the vicinities of Bekily are the main commercially available blue garnets.

References

1. Karl Schmetzer and Heinz-Jürgen Bernhardt, Garnets from Madagascar With a Color Change of Blue-Green to Purple. Gems&Gemology, Winter 1999, page accessed on the 26th November 2018.
2. Ambahatany. Mindat.org, page accessed on the 26th November 2018.
3. Farbwechselnde und blaue Granate. Mineralienatlas – Fossilienatlas. Page accessed in the 26th November 2018. Images of blue garnet crystals!

Blue garnets of Bekily are included in the following lists and articles:

Dominican amber

Some of the richest finds of amber (although less rich than the finds of Baltic amber) in the world are in the Dominican Republic. Amber here is found in Cordillera Septentrional mountains, in La Cumbre, La Toca, Palo Quemado, La Bucara, Los Cacaos and some other mines.

Two more amber finds are in the east of the country – Bayaguana and Sabana de la Mer.

Formation of amber

Dominican amber is mined from lignite layers which are found in Oligocene – Miocene sandstone deposits.

This amber started to form some 40 million years ago. Tropical rainforest was growing here and most abundant were the magnificent Hymenea protera trees.

These trees were rich with resin. It is possible that resin was hanging from the branches like stalactites – as it is observed in some moist tropical forest today. Resin accumulated in the soil around the tree.

Even more resin was produced when trees suffered from fire, e.g. lightning.

Later, as millions of years passed, deposits of this unusual forest descended below the sea level and covered with a thick layer of sediments. Gradually the resin transformed into amber.

Then, as the tectonic plates moved on, these sediments were rised out of the sea again and folded into mountains.

History of mining

Dominican amber was known to local Taíno people. Christopher Columbus received a gift – pair of shoes with beautiful beads of amber – on his first visit to America, on December 16, 1492.

Nevertheless this gem was of little interest to Europeans – until the middle of the 20th century.

After World War II West Germany lost free access to the finds of Baltic amber. One German company managed to obtain a mining license in the Dominican Republic in the 1950s – and their finds were that successful that the company was evicted from the country and it was forbidden to export raw amber.

Dominican amber obtained international fame in the 1990s when "Jurassic park" movies were made. Numerous mines – "rat holes" – have emerged over the last decades. Amber mining in the Dominican Republic for the most part is dangerous and exhausting occupation – mines are flooded in the rainy season and sometimes collapse.

Top quality amber

Dominican amber is superior to Baltic amber in several ways. It is much more transparent and fossil inclusions are found 10 times more frequently than in Baltic amber.

Dominican amber is much sought by scientists – new species of extinct insects, plants, and other life forms are found here on a regular basis. DNA of long-extinct animals was extracted from Dominican amber already in 1992.

The blue amber

Dominican amber is found in many colors – the traditional yellow, orange and brown, but also transparent, without color.

More rare is pink variety and most rare – blue. Only some 100 – 150 kg of blue amber are mined in a year. Miners tell that blue amber is found in Palo Quemado mine. This variety of amber does not contain fossils.

The blue amber is not truly blue – when looking through it towards the light, amber has the common orange – yellow color. It becomes blue, when light shines ON it.

This amazing effect is caused by the reflection of ultraviolet and violet color by polycyclic aromatic hydrocarbons in amber – e.g. other colors pass through it, but ultra-violet and deep blue is reflected, making the ultra-violet light visible. If put in ultra violet light, such amber shines in a lot more intense, deep blue color.

It is not known what has caused this unique effect in the amber from Palo Quemado mine – but this is very rare. Such amber is reported also from Chiapas, Mexico and several islands (Sumatra, Jawa, Kalimantan, Papua) of Indonesia.

References

1. Ambar Azul – The Direct Dominican Source for High Quality Amber – supplier of top class blue amber.

Palo Quemado blue amber mine are included in the following article: