More Unusual Gemstones for Collectors
There are many unusual gemstone varieties available today, many of which are considered to be lesser-known collector's gemstones, either because they are too rare or too fragile to wear as jewelry. However, just because they're classified as lesser-known collector's gems, it doesn't mean they're not important. Some unusual and lesser-known collector's gemstones include:
Scheelite is a calcium tungstate mineral named after Karl Wilhelm Scheele (1742-1786), a Swedish chemist. It is the primary ore for tungsten, an important metal for the jewelry industry that is often alloyed for the making of ring bands, pendants and necklaces. Scheelite is rarely found in gem-grade quality, rendering it one of the lesser-known gemstones of today. When cut and polished, scheelite has an attractive adamantine luster and high-quality crystals can exhibit excellent dispersion. Scheelite gemstones can be found in various colors including colorless, yellow, orange and brown. Scheelite deposits are found in various locations around the world, including Australia, England, Germany, Finland, Japan, Korea, Mexico, Peru, Spain, Sri Lanka and the United States (Connecticut, Utah, Arizona and California).
Painite is a rare borate mineral first discovered in Myanmar (Burma) by British mineralogist, Arthur C.D. Pain, in 1954. Gemstone quality crystals were not discovered until 2001. For several years, only 3 painite crystals were known to exist, and up until 2005, only 25 crystals painite crystals had been found. Since then, more material has been discovered in Northern Myanmar, but painite remains one of the rarest and most unusual gemstones. Myanmar (Burma) is the world's only source for painite today. Painite is relatively hard at 8 on the Mohs scale. Painite color can range from brownish to red, and it has a vitreous luster when polished. Only a modest amount of transparent painite has been cut into gemstones, most of which have been distributed to institutions such as the British Museum of Natural History, GRS and GIA.
Gahnite is an unusual gemstone often referred to as 'zinc spinel'. The mineral was named after Swedish chemist, Johan Gottlieb Gahn, who was the first to discover the unique mineral in 1807. Gahnite belongs to the important group of spinel gemstones. When zinc replaces all of spinel's magnesium content, the result is the unusual rare variety of zinc spinel we know as gahnite. Gahnite's color is normally very dark, often black in color, but some materials have been found in others colors such as blue, yellow, green, red and violet. Gahnite has a hardness of 7.5 to 8 on the Mohs scale, but owing to its rarity, it is usually faceted only for collectors.
Brazilianite is an unusual gemstone named after the country of Brazil, where it was first discovered in 1944. It one of the very few phosphate minerals used as gemstones. Other phosphates include apatite and turquoise. Brazilianite is a relatively new gemstone discovery, but it is becoming a collector's favorite. Fine materials have excellent transparency and a vitreous luster. Its color is usually similar to that of chrysoberyl, but it can also be colorless. Brazilianite has a hardness rating of just 5.5 on the Mohs scale, which makes it rather soft, though it is one of the hardest of phosphate gemstone varieties. Despite being named after and discovered in Brazil (Minas Gerais), brazilianite is also found in New Jersey, United States.
- 初刊: November-13-2014
- 最終アップデート: January-23-2019
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