Chemical Formula: Pb2As2S5
Locality: Binnental, Valais, Switzerland.
Name Origin: For Ours Pierre Armand Petit Dufrenoy (1792-1857), French mineralogist, National School of Mines, Paris, France.
Physical Properties
Cleavage: {010} Perfect
Color: Lead gray, Gray, Steel gray.
Density: 5.55 – 5.57, Average = 5.56
Diaphaneity: Subtranslucent to opaque
Fracture: Brittle – Conchoidal – Very brittle fracture producing small, conchoidal fragments.
Habit: Massive – Uniformly indistinguishable crystals forming large masses.
Hardness: 3 – Calcite
Luster: Sub Metallic
Streak: red brown
Photo
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