Rare Gem Sphalerite From Spain

Write By: tmmadmin Published In: Classic Mineral Localities Created Date: 2015-10-09 Hits: 9381 Comment: 0

Sphalerite cut gemstones

Sphalerite gem rough

Sphalerite is a zinc sulphide mineral (Zn,Fe)S that is the chief ore of zinc. While common as massive ore and crystals, gem quality rough is extremely rare. Gems that display flashes of light are prized for their exceptional fire, which is the result of the dispersion of white light into the separate spectral colors. Top grade gem sphalerite specimens exhibit a dispersion value of 0.156, which is three and a half times higher than that of diamonds, at 0.044. In measurements of how light passes through sphalerite, it has a refractive index of 2.37, just slightly less than diamond, at 2.42. Sphalerite is a fairly dense stone, with a specific gravity of around 4.0, so even small cut stones will weigh a comparatively high number of carats for their size.

1.5" 44g Fruity Gemmy Orange Sphalerite Crystal Picos de Europa Spain for sale

Most sphalerite contains iron, and the more iron that is present, the blacker and more opaque the sphalerite. Conversely, gem quality specimens have a low iron content and thus have a high degree of transparency. Colors range from red to orange, yellowish to golden brown, and green. Because it has a hardness of only 3.5 to 4 on the Mohs scale, it is it is mainly a gemstone for the rare stone collector. It is not suitable for rings, but can be used in pendants and earrings.

2.4" Semi-Transparent Red Orange Gemmy Sphalerite Crystal Group Spain for sale

The best gem sphalerite in the world came from the Aliva mine in the Picos de Europa Mountains in the Cantabria region on the north coast of Spain. The mine closed in 1989 and is now inside the boundaries of a national park. Spanish sphalerite is now quite scarce because all of the gems and gem rough on the market came from material that was mined years ago.

© Copyright 2015 Treasure Mountain Mining

Leave A Comment