Berthierite

Not to be confused with Berthierine, a phyllosilicate from the serpentine subgroup.

Berthierite
File:Berthierite-224182.jpg
General
Category	Minerals
Formula	FeSb2S4
IMA symbol	Btr
Strunz classification	2.HA.20
Crystal system	Orthorhombic
Crystal class	Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m)
Space group	Pnam
Identification
Color	Steel grey
Cleavage	Poor/indistinct
Mohs scale hardness	2–3
Luster	Metallic
Diaphaneity	Opaque
Specific gravity	4.64

Berthierite is a mineral, a sulfide of iron and antimony with formula FeSb₂S₄ (FeS·Sb₂S₃). It is steel grey in colour with a metallic lustre, which an iridescent tarnish can cover. Because of its appearance, it is often mistaken for stibnite (Sb₂S₃, an antimony trisulfide mineral, free of Fe²⁺ sulfide).

It was discovered in France in 1827 and named for the French chemist, Pierre Berthier (1782–1861).

Berthierine, an iron(II)-rich phyllosilicate from the serpentine subgroup, with as chemical formula (Mg,Fe)₃(Si₂O₅)(OH)₄, was also named in honor of Pierre Berthier. The great similarity between the two names is a frequent source of confusion between these two very different mineral species.

See also

• List of minerals
• List of minerals named after people

External links

• Mineral galleries
• Mindat
• Webmineral