Uzonite

General Information: Chemical Formula:As4S5 Composition:(Molecular Weight = 460.02 gm)Arsenic 65.15 % AsSulfur 34.85 % S  Empirical Formula: As4S5 Locality:Uzon caldera, Kamchatka, Russia. Name Origin:Named for the locality.Physical Properties: Cleavage:[001] Distinct Color:yellow. Density:3.37 Habits:Microscopic Crystals - Crystals visible only with microscopes., Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline)., Hardness:1.5 - Between Talc and Gypsum Luster:Pearly Streak:yellowMore details...