Hancockite

General Information: Chemical Formula:(Pb,Ca,Sr)2(Al,Fe+++)3(SiO4)3(OH) Environment:Metamorphosed zinc deposit. Locality:Franklin, New JerseyPhysical Properties: Cleavage:[001] Perfect Color:brown, brick red, brownish red, or maroon. Density:4 Diaphaniety:Translucent Habits:Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline)., Striated - Parallel lines on crystal surface or cleavage face., Hardness:6-7 - Orthoclase-Quartz Luminescence:Non-fluorescent. Luster:Vitreous - Dull Streak:brownish whiteMore details...