Mineral Species: Sphalerite and Quartz
Chemical Formula: ZnS
Chemical Name: Zinc Sulfide
Mineral Class: Sulphide
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: A grey limestone matrix covered by a thick blanket of white Quartz. The Quartz itself is highly attractive being very gemmy due to the mineral's almost water-like transparency. Adding to the aesthetic appeal are the numerous clusters of black Sphalerite crystals. Besides providing a striking contrast they are interesting mineralogically because of twinned dodecahedral crystals.
Location: Smallcelugh Mine, Nenthead, Cumbria, England.
