Formula: Pb4Sb6S13
Crystal System: Monoclinic
Specific gravity: 6.7 measured, 6.87 calculated
Hardness: 2½ to 3
Streak: Grey
Colour: Lead-grey
Common impurities: Bi

Hydrothermal environments

Robinsonite is a primary hydrothermal mineral associated with zinkenite, boulangerite, semseyite, plagionite, stibnite, sphalerite, galena, pyrite, quartz and calcite (HOM).


The type locality, the Red Bird Mine, Antelope Springs Mining District, Pershing county, Nevada, USA, is a low temperature hydrothermal deposit. Here robinsonite occurs as a primary mineral with pyrite, sphalerite, stibnite and boulangerite in small pieces in oxidised ore bodies. The gangue minerals identified are quartz, calcite and aragonite variety tarnowitzite. A slab about 1 cm thick was cut through the analysed sample. The slab is composed of boulangerite and robinsonite, and the core is speckled by small inclusions of quartz, usually rimmed by tiny crystals of pyrite. A few small areas of bindheimite are also seen within the boulangerite - robinsonite mass. This mass is completely rimmed by about a centimeter of the alteration product bindheimite. Small inclusions of minium are found in the bindheimite (AM 37.438-446).

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