Every gemstone species has its interesting quirks, but spodumene is intriguing not only for its quirky name. It is a major source of the rare element lithium, itself a fascinating metal. Lithium is the lightest of all metals and the least dense solid element known to man. Lithium has many important industrials applications, including heat-resistant glass and ceramics, mood stabilizing drugs, aircraft alloys and lithium batteries.
Spodumene draws its unusual name from the Greek spodumenos, meaning ash-colored, in reference to the color of non-gem spodumene crystals. Gem-quality spodumene is rather more colorful, ranging from colorless to yellow, pink to violet, and yellowish-green to medium-deep green. But gem-quality spodumene occurs very rarely, and the two best known varieties -- hiddenite and kunzite -- were discovered only in the last 130 years.
By chemical composition, spodumene is a lithium aluminum silicate with a hardness of 6.5 to 7 on the Mohs scale. It has a vitreous luster, excellent transparency and good brilliance; its refractive index (1.660 - 1.681) is just slightly less than that of tanzanite. It is moderately dense, with a specific gravity of 3.15 to 3.21. It has perfect cleavage, a property is shares with diamond and topaz. It also has very pronounced pleochroism, meaning that it displays different colors when viewed from different angles.
The yellow variety of spodumene is known simply as spodumene, while the green and pink varieties are known respectively as hiddenite and kunzite. A colorless variety has recently been discovered in Madagascar, and a few very rare specimens of a light blue spodumene have been found in Afghanistan. While most of the world's supply of gem-quality spodumene comes from Afghanistan, Pakistan, Madagascar and Brazil, the first specimens of both hiddenite and kunzite were discovered in the USA.
Hiddenite was named after W.E. Hidden. Hidden was a mineralogist who was sent by Thomas Edison to North Carolina to look for platinum. He discovered hiddenite instead. The green variety of spodumene is colored by traces of chromium. In order to display strong colors, the table facets must be perpendicular to the main axis of the stone. The top and bottom of the crystal reveal the deepest colors and expert gem cutters take advantage of its effects.
Kunzite was first discovered in San Diego County, California in 1902 and named in honor of George Frederick Kunz, the legendary American gemologist. It ranges in color from a pale pink, violet or lilac to a medium pink. Kunzite is colored by traces of manganese. It is recommended that kunzite not be exposed to strong light since the delicate color is known to fade over time. For this reason kunzite is sometimes called the "evening" stone.
- First Published: February-18-2008
- Last Updated: March-09-2011
- © 2005-2014 GemSelect.com all rights reserved.
Reproduction (text or graphics) without the express written consent of GemSelect.com (SETT Company Ltd.) is strictly prohibited.