Tsavorite

Emerald is one of the most desirable of all gemstones, largely because of the purity and intensity of its green color. Until tsavorite was discovered in the late 1960's there was no other gemstone but emerald that could offer the gem buyer a rich, dark green color. This magnificent green garnet has been in great demand for jewelry since its discovery, and for good reasons: it is harder than emerald, more durable in jewelry, less included than emerald, more brilliant when faceted, and is much rarer than emerald. In short, it is (by all counts) a better gemstone, but it lacks the magic and the antiquity of the name "emerald". For this reason it is known to far fewer people, is in much lower demand, and is therefore much less expensive than emerald of comparable color.

Tsavorite was first unearthed in Tanzania and Kenya; the name "tsavorite" is actually a trade name created by Tiffany and Co., in reference to the Tsavo National Park in Kenya (located near the tsavorite locality). The material has more than tripled in price since its introduction to the marketplace, but at current price levels it still sells at a tenth or less of the price of emerald of comparable quality. Stones over 2 carats are extremely rare, and 5+ carat gems of fine color are virtual museum pieces.

The geology of tsavorite is such that the supply is extremely sporadic. Most of the rough is highly shattered in place (due to earth movements over the centuries), which accounts for the great rarity of large, clean stones. The projected future availability is not optimistic, which indicates the potential for significant upward price movement.