Mineral Species: Sphalerite
Chemical Formula: ZnS
Chemical Name: Zinc Sulfide
Mineral Class: Sulfide
Mineral Notes: Sphalerite is a common sulfide and an important ore of Zinc. It is often called Zincblende or Black Jack. The mineral most commonly occurs in hydrothermal veins in all types of rock, especially with other sulfides, like Galena. Nearly all Sphalerite contains some Iron in solid solution, which affects its appearance and properties. Identification is made on the basis of its perfect cleavage and resinous luster.
Description: Large, black crystals of Spahlerite on Quartz matrix. These are extremely lustrous and therefore gemmy. There is considerable twinning but individual crystal outlines are easily seen. One end of the specimen is covered by tiny crystals of Pyrite.