Straw-yellow crystal aggregates of the extremely rare mineral santanaite from the type and only known locality worldwide (Santa Ana Mine, Sierra Gorda District, Antofagasta Region, Chile). Santanaite is a lead chromate. Ex. F.Bauer collection. The specimen was bought to the very reputed seller H.Wilke (Germany) in 1989. — Photo: David Hospital · CC BY-SA 4.0
Santanaite
Santanaite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Pb₁₁CrO₁₆.
It crystallizes in the hexagonal crystal system (space group P6_322).
Key properties: Mohs hardness 4; specific gravity 9.155; Adamantine luster; optically uniaxial.
IMA symbol San, IMA status: approved, named in 1971.
An alteration product of galena with other chromium-bearing minerals in an oxidized hydrothermal lead deposit.
It is found associated with Galena, phoenicochroite, chromatian wulfenite, diaboleite, quartz.
The name refers to the occurrence at the Santa Ana mine, Chile.