Stibiconite

Stibiconite
Stibiconite. Locality: Catorce (Real de Catorce), Municipio de Catorce, San Luis Potosí, Mexico (Locality at mindat.org)
General
Category	Oxide minerals
Formula (repeating unit)	Sb3+Sb5+2O6(OH)
IMA symbol	Sbc[1]
Strunz classification	4.DH.20
Crystal system	Isometric
Crystal class	Hexoctahedral (m3m) H-M symbol: (4/m 3 2/m)
Space group	Fd3m
Unit cell	a = 10.27 Å; Z = 8
Identification
Formula mass	478.25 g/mol
Color	Pale yellow to yellowish white, reddish white, orange; gray, brown, black when impure
Crystal habit	Massive, botryoidal, as incrustations, powdery
Cleavage	None
Fracture	Clay-like
Mohs scale hardness	4-5
Luster	Vitreous - dull
Streak	light yellow
Diaphaneity	Transparent to translucent
Specific gravity	4.1 - 5.8, Average = 4.94
Optical properties	Isotropic
Refractive index	n=1.6-1.97
References	[2][3][4]

Stibiconite is an antimony oxide mineral with formula: Sb₃O₆(OH). Its name originates from Greek "stibi" (antimony) and "konis" (powder), alluding to its composition and habit.^[2][3][4] It is a member of the pyrochlore super group.

Discovery and occurrence[]

It was first described in 1862 for an occurrence in the Brandholz - Goldkronach District, Fichtelgebirge, Franconia, Bavaria.^[3]

It occurs as a secondary alteration product of other hydrothermal antimony minerals such as stibnite. It occurs in association with cervantite, valentinite, kermesite, native antimony and stibnite.^[4]

References[]