Formula: Sb2O3

Colour: Colourless to gray

Lustre: Sub-Adamantine, Resinous

Hardness: 2 – 2½

Specific Gravity: 5.5

Crystal System: Isometric

Name: Named by J.D. Dana in 1851 in honor of Henri Hureau de Sénarmont (6 September 1808, Broué, France – 30 June 1862, Paris, France), Professor of Mineralogy, School of Mines, Paris, who first described the species. De Sénarmont also made significant contributions to the study of polarization and demonstrating the anisotropy of heat diffusion in a crystal.

Type Locality: Djebel Hammimat Mine, Aïn Babouche, Ain Babouche District, Oum el Bouaghi Province – Algeria

Dimorph of: Valentinite

Isostructural with: Arsenolite