Dervillite is a monoclinic-prismatic brownish-black mineral, containing sulfur, silver, and arsenic.
It was named after Dr. Henri Dervile of Strasbourg University in Strasbourg, France, who observed the original specimen.
Properties of Dervillite
The following are the key properties of Dervillite:
- Cell Data
- Space Group: P2/a
- a = 6.833
- b = 12.932
- c = 9.638
- β = 99°33'
- Z = 
- Crystal Data
- Point Group: 2/m
- Minute crystals, to 0.3mm
- X-ray Powder Pattern: 3.075 (10), 3.019 (8), 2.843 (5), 3.251 (3), 2.659 (3), 3.170 (2), 2.742 (2)
- Chemical Composition
- Estimated Properties
||Bulk density (electron density) = 2.52 g/cm3
note: Specific gravity of Dervillite = 2.81 g/cm3
||PEDervillite = 170.89 barns/electron
U = PEDervillite x ρElectron density = 430.40 barns/cm3
||Fermion index = 0.0013
Boson index = 0.9986
||Dervillite is not radioactive
How to Identify Dervillite
Dervillite can be identified by its brownish-black color, having metallic luster, black streak, and good cleavage.
It is opaque, with a relative hardness ranging from 1 to 1.5.
Dervillite is mainly observed in museum specimens from the Gabe-Gottes mine, Rauenthal, near Sainte-Marie-aux-Mines, Haut-Rhin, France.
Occurrence of Dervillite and Useful Mineral Association
Dervillite occurs in a Co–Ni–Fe–As deposit.
Quartz, calcite, proustite, safflorite, rammelsbergite, and arsenic are the minerals that are closely associated with dervillite.