Cornetite
Formula: Cu3(PO4)(OH)3
Species: Phosphates
Colour: Dark blue to green-blue; green-blue in transmitted light.
Lustre: Vitreous
Hardness: 4½
Specific Gravity: 4.10
Crystal System: Orthorhombic
Name: Named in honor of Mr. Jules Cornet (1865-1929), Belgian geologist. He prospected in the Congo and particularly in Katanga where he discovered its immense mineral wealth.
Type Locality: L’Etoile du Congo Mine, Lubumbashi, Haut-Katanga, DR Congo