Tsavorite: when Garnet is Green
The gemstone discoveries in East Africa in the 1960s transformed the jewelry world: new varieties, new colors, and new variations on existing species made that decade the most exciting time in the gemstone industry in our lifetimes.
The chain of discoveries was breathtaking: raspberry-red rhodolite garnet, a rainbow of fancy sapphire, rich red ruby, grass-green chrome tourmaline, the sunset hues of malaya garnet, and velvety-blue tanzanite. The grand finale was the discovery in 1968 in Tanzania of a magnificent brilliant green grossular garnet. The beautiful green garnet was also discovered on the Kenya side of the border in 1971, National Park game preserve in Kenya by Tiffany & co in New York, who introduced the gemstone to the world market.
Tsavorite has a beautiful vivid green color, is bright and lively with a high refractive index, and has a garnet's durability and high clarity.
Tsavorite comes from the East African bush: all the mines currently producing are in an arid grassy are with bare dry hills that runs across the border from Kenya to Tanzania. This area is home to snakes and an occasional lion.
Hundreds of millions of years ago, this land was covered by the ocean. Layers of organic sediment were deposited, eventually forming shale. Then the land was subjected to intense heat and pressure, folding and rocks gave birth to unusual gemstones of East Africa, many colored by the vanadium which is plentiful in these rocks because of their organic history in the ocean floor.
The heat and folding of the rock hundreds of millions of years ago which formed tsavorite also shattered most of the crystals. It is very rare to find tsavorite in sizes larger than five carats, and most faceted stones are below two carats. Many deposits of tsavorite are small and unpredictable: seams suddenly narrow and disappear, giving no indication where to look next.
Last year a new tsavorite-producing area was discovered in Lokirima, about a thousand kilometers northwest of the previously known localities. Although this locality is only producing a small quantity, it is promising that the possibility of finding tsavorite exists over a wider area than previously thought.
How rare is too rare?
Perhaps the association with demantoid has hurt tsavorite: The rarity of the stone has led jewelers around the world to treat tsavorite as a specialty item, like alexandrite.
One of the tsavorite miners in Kenya has begun a promotional program in conjunction with a dealer in Idar-Oberstein to try to convince jewelers that, in small sizes, tsavorite is reliably available as a durable and attractive green gemstone. The dealer is offering calibrated and fancy-cut tsavorite in unusual shapes as well as a line of tsavorite jewelry with tapered tsavorite baguettes and surprising uses of tsavorite.
The campaign may be starting to work: Tsavorite has also begun to appear in magnificent invisibly-set jewelry, where its durability and clarity are a distinct advantage.
But tsavorite still needs to break out of a cycle of demand caused by lack of supply. There is potential for mining tsavorite in other areas of Kenya but development of new mining areas, which requires investment in machinery and high operating costs, is unlikely until demand rises. And demand hasn't started to rise because the supply is too limited.
Eventually, the beauty of tsavorite is bound to win over consumers. All they need is to see tsavorite to appreciate its appeal. The recent widening of the market for tanzanite, which came through an increase in the supply available, may convince more retail jewelers to take a chance on tsavorite. Once given this chance, East Africa's beautiful green garnet will surely find its proper place in the gemstone rainbow.