Barytes

Chemistry: Barium sulphate
Crystal system: Orthorhombic; crystals often tabular; massive & stalagmatic form; rosette aggregate form.
Color: Transparent to opaque; colorless, blue, yellow, red, brown, green; massive white.
Hardness: 3
Cleavage: Perfect; in 3 directions, brittle; Fracture: uneven
Specific gravity: 4.3 – 4.6
Refractive index: 1.636 – 1.648; Biaxial positive; 0.012
Luster: Vitreous
Occurrence: Worldwide; Canada, USA, England, Germany, Spain.

Notes
Barytes is also called Barite (or Heavy Spar); massive white may resemble marble; some shows stalagmatic formation; crystal aggregates in the form of rosettes is often known as ‘desert roses’; fluorescent specimens may show faint blue/green colors; usually cut for collectors.