Adamite

Adamite – Zn2(AsO4)(OH)
Elements: Zinc, Arsenic, Oxygen, Hydrogen
Class: Arsenates
Crystal System: Orthorhombic
Hardness: 3.5
Fluorite
Talc (1)Diamond (10)
Softer than glass. A steel knife scratches it.
Size: 8.7 x 7.6 x 1.7 cm Origin: Ojuela Mine, Mapimi, Durango – Mexico