Asian tastes for jewellery are slowly changing from the traditional and well loved Rubies, Emeralds, Sapphires and Diamonds to other exciting and equally beautiful alternatives. What is not so well known is that today is that over 4,700 species of minerals have been recognized to date, and there are at least 100 proposals for new minerals submitted each year!   Not every mineral will pass as a “gem” but if Beautiful, Durable and to some extent Rare these factors would qualify the mineral as a Gem.  This means that today we truly have a great selection of beautiful Gems to choose from which can be enjoyed and appreciated as much as the more commonly recognized offerings.

Sample of garnet from JDMIS' gemmology course

Garnets in every Colour!

Garnets have an interesting history found to date back to the Bronze Age. Although a majority of garnets come in red (leading to the erroneous belief that all garnets are red) the Garnet group is actually much larger than most people realize.

Red garnet's relative abundance and widespread use has contributed to a lower price than other gems in its league, but the more rare Tsavorite (green), Mandarin (orange) and Blue (change of colour) garnets are amongst the most valuable and fashionable gem materials and can be found in the latest high jewellery collections around the globe. The most expensive blue Garnet, of just over 4cts, sold for $6.8 million in 2003.

Unlike nearly every other gem material, Garnet is also one of the few gems can be considered truly natural – it is not commonly treated in any way – making even affordable specimens uniquely ‘all-natural’.  Despite the profusion of garnets available today, this beautiful and varied gem material remains a popular choice for collectors with an interest in its long history, eye for its beauty and desire for its durability and affordability.

Sample of spinel from JDMIS' gemmology course

Spinel – Now more rare than Ruby

Spinel is a gem that has often been overshadowed by Ruby, but as more people have come to discover this beautiful mineral it has emerged from the shadows and is finally receiving recognition as a treasured gem in its own right.  It is sought after by gem dealers and collectors on account of its brilliance, hardness and wide range of spectacular colours.   In addition to beautiful rich reds which imitate ruby and rare cobalt blue hues that convincingly look like blue sapphire.  Spinel can also be found in a range of gorgeous pastel shades of pink, purple and even some ‘change-of-colour’ specimens.

Spinel is not only an attractive but a historically important gem that has been commonly mistaken with ruby for centuries and so many of these famous red gems set in Royal crown jewels and exclusive collections around the world have now been discovered to be spinel.  Some of the best red, pink and orange spinels are uncovered in Burma’s Mogok Stone Tract. The best blue and violet colours come from Sri Lanka, black colours are found in Thailand. Spinel is also mined in Vietnam, Tanzania, Madagascar and the Pamir mountains of Tajikistan.

In modern jewellery, Spinel is  gaining popularity and is now commonly recognized by dealers and connoisseurs as an exceptionally rare and valuable gem, on par with rubies and sapphires, in fact Red Spinel is now said to be more rare than Ruby!


Sample of tanzanite from JDMIS' gemmology course

Tanzanite – More rare than Diamonds

This amazing gem is very young compared to the traditional gems found centuries ago.  It was discovered by Masai Tribesmen as recently as 1967, and is only found in one place on earth: Tanzania, East Africa; hence its name Tanzanite. The only known deposit of tanzanite is located on a hilltop, an area only around 5 miles long by 1 mile wide.  Tanzanite was given its name by Tiffany & Co, who recognized the beauty and value of this alluring gemstone and started to promote it in 1968 but still today there are many who have not yet discovered this enticing gem.

Sample of tanzanite from JDMIS' gemmology course

Tanzanite is pleochroic, which means that it shows different colours depending on the viewing angle.   This means that Gem cutters must properly orient tanzanite In order to get the preferred blue or violet-blue hue from the face-up position. The vivid blue of tanzanite can rival any fine sapphire and the natural crystals are routinely heated to enhance these fine blue and violet hues.  Although Tanzanite is usually clean to the eye, today mostly small crystals are found, with occasionally a large crystal of excellent quality. 



Sunstone, an alternative to Moonstone.

 Sunstone is from the Feldspar Group of minerals and is formed from crystals in cooling lava flows.  Moonstone is found in the same mineral Group.   Mainly mined in Oregon, USA this gem commonly occurs in pale yellow, shades of red, orange, and even green.   It exhibits an unusual feature known as the Schiller effect, in which tiny silk-like inclusions in the gemstone reflect light making it appear to glow as if from an internal light source; it is because of this fiery effect that the gem got its name.   Sunstone is not treated or altered in any way when used in jewellery.   This is one of the most naturally appealing gems, relying on its inherent beauty and glow. The reddest sunstones typically are the most valuable, and each one looks very unique in appearance.

Sample of moldavite gemstone from JDMIS' gemmology course

Moldavite the gem from Outer Space

Moldavite is found in the Czech Republic.  It extraterrestrial in nature, as these crystals were formed about 20 million years ago when meteors crashed to the Earth.  The impact of these meteorites hitting the rock on earth caused the existing rock to melt and fuse with the meteors, creating a new crystal made of both extraterrestrial and terrestrial material.  It belongs to the Tektite group of minerals, which is a small family of natural glass rocks.

Moldavite is usually a deep bottle green with natural surface etchings, and is translucent when held up to light.  Pieces vary in size and thickness.  

The total amount of moldavite in the world is estimated to be about 275 tonnes'  worth.  Previously, there were four moldavite mines in operation throughout the Czech Republic, but today only one pit remains, which legally produces moldavite on a commercial level.  It is estimated that all gem-quality moldavite will be completely exhausted in about ten years' time.

The world of gems awaits discovery at the JDMIS

If you are interested to discover more about these and many other interesting gems you are in luck as you will not have to travel too far!  The JDMIS,  Jewellery Design and Management International School, is central and open to all who love gems and jewellery.  Providing exceptional education to the jewellery trade and to aficionados and collectors in Singapore and the region, its most popular course is entitled ‘Gem and Jewellery Trade Secrets’. Participants in this exclusive course explore the world of gems and jewellery using over 1800 gem exhibits, allowing them to see and examine natural, treated and imitation specimens to fully appreciate the variety of gems on the market. Limited to only 8-12 participants, this fascinating course is personally taught by me in the new blended (hybrid) learning mode and remains the JDMIS’ highest rated jewellery programme.

Tanja M. Sadow G.J.G.
Dean and founder of the Jewellery Design and Management International School

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