Willemite
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Willemite is a zinc silicate mineral and a minor ore of zinc. It is highly fluorescent under shortwave ultraviolet light. It occurs in a variety of colors in daylight, in fibrous masses and apple-green gemmy masses. Wikipedia
Cleavage: – imperfect
Crystal class: Rhombohedral (3); (same H-M symbol)
Crystal habit: Fibrous, botryoidal to massive
Crystal system: Trigonal
Formula (repeating unit): Zn2SiO4
Fracture: Irregular to conchoidal
Luster: Vitreous to resinous