Sphalerite- Luster Metallic, sub-metallic, Cleavage 1,all sides, forming a dodecahedron Hardness 3.5 - 4 Color Black, brown, red, orange, yellow, green, gray. Streak Pure Sphalerite has a white streak. However, impurities are almost always present, giving this mineral a light brown streak. The streak will always be a lighter color than the specimen Composition Zinc sulfide, usually with some iron, sometimes with magnesium, manganese.
Zinc, in commerce also spelter, is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element of group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2. Zinc is the 24th most abundant element in the Earth's crust and has five stable isotopes. The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral.
Zinc sulfide - Mixtures of zinc and sulfur react pyrotechnically, leaving behind zinc sulfide - Zinc sulfide (or zinc sulphide) is an inorganic compound with the chemical formula of ZnS. This is the main form of zinc found in nature, where it mainly occurs as the mineral sphalerite. Although this mineral is usually black because of various impurities, the pure material is white, and it is widely used as a pigment.