Sphalerite
Sphelarite
Sphalerite (which is also known as Blende), is an important ore of zinc and can make a rather attractive cabinet specimen as well. It can have excellent luster and associates with many beautifully colored minerals making it one of the best enhancers of many fine mineral specimens.
Sphalerite is one of the very few minerals that has a total of six directions of cleavage. If all of them were to be perfectly cleaved on a single crystal it would form a rhombic dodecahedron. Identifying all six directions in a single cleaved crystal is quite difficult due to the multiple twinning and the many directions. Only the fact that there is abundant cleavage at different directions can easily be seen in most cleaved specimens.
Sphalerite is a zinc sulphide and is best known in the mineral world as the chief ore of zinc. Most sphalerite contains iron and when the iron content is high it is an opaque black. The rare gem-quality crystals have a very low iron content and considerable transparency. They are typically a yellowish to honey brown, red to orange, or green.
The two most important sources for gem-quality sphalerite are the Chivera mine in Sonora, Mexico; and the Picos de Europa, near Santander on Spain’s northern coast. Sphalerite is also found in Namibia and the Congo.
Sphalerite is considered to be a semi-precious gemstone and while limited in nature, gems of good color and size are available, however, faceted stones above 1 carat are rare. Despite being soft and somewhat fragile, Sphalerite’s brilliance, dispersion greater than diamond, deep earthy colors and vivid three dimensional inclusions, make it a unique and exquisite gemstone that is keenly sought after by gemstone collectors and connoisseurs alike