Livingstonite

Livingstonite is a mercury antimony sulfosalt mineral. It occurs in low-temperature hydrothermal veins associated with cinnabar, stibnite, sulfur and gypsum.

Livingstonite
Bright, steel-metallic livingstonite laths to 1.2 cm. on rich antimony (stibnite) ore. From the type locality in Huitzuco de los Figueroa.
General
Category	Sulfosalt mineral
Formula (repeating unit)	HgSb4S8
Strunz classification	2.HA.15
Crystal system	Monoclinic
Crystal class	Prismatic (2/m) (same H-M symbol)
Space group	A2/a
Unit cell	a = 30.567(6), b = 4.015(1) c = 21.465(3) [Å]; β = 103.39°; Z = 8
Identification
Color	Blackish gray; in polished section, white; red in transmitted light, with deep red internal reflections
Crystal habit	As needles elongated [010], to 12 cm; also fibrous, massive, columnar, and in globular masses and interlaced needles.
Cleavage	Perfect on {001}, poor on {010} and {100}
Fracture	Uneven, flat surfaces
Tenacity	Flexible
Mohs scale hardness	2
Luster	Adamantine to metallic
Streak	Red
Diaphaneity	Opaque, translucent in thin fragments
Specific gravity	4.8 - 4.88 meas. 4.98 calc.
Optical properties	Biaxial (–)
Refractive index	>= 2.72
Pleochroism	Weak; strongly anisotropic
References	[1][2][3]

It was first described in 1874 for an occurrence in Huitzuco de los Figueroa, Guerrero, Mexico. It was named to honor Scottish explorer of Africa, David Livingstone.[4]

Its crystal structure was determined in 1957[5] and redetermined in 1975.[6]