Daubréelite

Daubréelite
Coahuila meteorite fragment ("type locality"), Mineralogical Museum, Natural History Museum, Harvard University
General
Category	Sulfide mineral
Formula (repeating unit)	Fe2+Cr3+2S4
Strunz classification	2.DA.05
Dana classification	02.10.01.11
Crystal system	Cubic
Crystal class	Hexoctahedral (m3m) H-M symbol: (4/m 3 2/m)
Space group	Fd3m
Unit cell	a = 9.966 Å; Z = 8
Identification
Color	Black
Crystal habit	Massive, platy aggregates, exsolution lamellae in troilite
Cleavage	Distinct
Fracture	Uneven
Tenacity	Brittle
Mohs scale hardness	4.5-5
Luster	Metallic
Streak	Brown or black
Diaphaneity	Opaque
References

Daubréelite is a rare sulfide mineral. It crystallizes with cubic symmetry and has chemical composition of Fe²⁺Cr³⁺₂S₄. It usually occurs as black platy aggregates.

Daubréelite was named after the French mineralogist, petrologist and meteoriticist Gabriel Auguste Daubrée. The mineral was first described in 1876 in the American Journal of Science. Its type locality is the Coahuila meteorite, Bolsom de Mapimí, Coahuila, Mexico.

In the Nickel-Strunz classification daubréelite is part of the "Sulfides and Sulfosalts" and further a "metal sulfide with a metal-sulfide ratio of 3:4 and 2:3".

Daubréelite is found in iron meteorites as an inclusion in meteoric iron (kamacite and taenite). Further paragenetic minerals are alabandine, enstatite, graphite, plagioclase and schreibersite.

According to one source daubréelite has been described from 34 localities. Some notable examples being the ALH 84001 meteorite, Hoba meteorite, and the Canyon Diablo meteorite.

The mineral was also found in the Hadley Rille meteorite which was retrieved by the Apollo 15 mission in the Rima Hadley (Mare Imbrium).