Andorite

Andorite is a sulfosalt mineral with the chemical formula PbAgSb₃S₆.

Andorite
Andorite - Itos Mine, Oruro City, Cercado Province, Bolivia. Specimen height is 4.1 cm.
General
Category	Sulfosalt mineral
Formula (repeating unit)	PbAgSb3S6
Strunz classification	2.JB.40a
Crystal system	Orthorhombic
Crystal class	Pyramidal (mm2) H-M symbol: (mm2)
Space group	Pn21a (andorite VI, senandorite)
Unit cell	a = 12.99, b = 19.14, c = 4.3 [Å]; Z = 4
Identification
Color	Dark steel-gray, may tarnish yellow or iridescent; white in polished section
Crystal habit	Crystals stout prismatic to tabular on {100}, striations parallel to [001]; massive
Twinning	On {110}
Cleavage	none observed
Fracture	conchoidal
Mohs scale hardness	3 - 3.5
Luster	metallic
Streak	Black
Diaphaneity	Opaque
Specific gravity	5.33 - 5.37
Optical properties	anisotropic
References	[1][2]

It was first described in 1892 for an occurrence in the Baia Sprie mine, Baia Sprie, Maramures County, Romania, and named for Hungarian amateur mineralogist Andor von Semsey (1833–1923).[1][3] Andorite occurs in low-temperature polymetallic hydrothermal veins. It occurs associated with stibnite, sphalerite, baryte, fluorite, siderite, cassiterite, arsenopyrite, stannite, zinkenite, tetrahedrite, pyrite, alunite, quartz, pyrargyrite, stephanite and rhodochrosite.[2]

References

1. "Andorite: Mindat mineral information and data". 2010. Archived from the original on 21 January 2010. Retrieved 5 February 2010.
2. Handbook of Mineralogy
3. "Andorite Mineral Data". 2010. Archived from the original on 17 January 2010. Retrieved 5 February 2010.

Sharp crystals of andorite (to 7 mm) with stannite matrix, San José Mine, Oruro Department, Bolivia