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	PbAgSb3S6
IMA symbol	Ado[1]
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	[2][3]

It was first described in 1892 for an occurrence in the Baia Sprie mine, Baia Sprie, in what is now Maramureș County, Romania, and named for Hungarian amateur mineralogist Andor von Semsey (1833–1923).^[2][4] 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.^[3]