Formula: Sb2O3

Colour: Colourless, white, light gray, light yellow

Lustre: Adamantine, Pearly

Hardness: 2½ – 3

Specific Gravity: 5.76

Crystal System: Orthorhombic

Name: Named after Basilius Valentinus (Basil Valentine) [1394 Mainz, Germany – 1450 “Germany?”], who wrote about the properties of antimony. Valentinus may have been a real 15th-century chemist but some historians argue that it was a pseudonym used by one or more 16th-century German authors.

Type Locality: Les Chalanches Mine, Allemond, Grenoble, Isère, Auvergne-Rhône-Alpes, France

Dimorph of: Senarmontite