Arhbarite
Formula: Cu2Mg(AsO4)(OH)3
Colour: Dark blue to medium blue
Lustre: Sub-Vitreous, Waxy
Crystal System: Triclinic
From: El Guanaco Mine, Guanaco (Huanaco), Santa Catalina, Antofagasta Province, Antofagasta Region, Chile.
Photo: Christian Rewitzer
