Opaque, cross-shaped staurolite "twins" are used in jewellery more often than the transparent stones, which are rare and cut only for collectors. "Cross-stones", as twins are called, have been used as amulets and in religious jewellery. Crystals are reddish brown to black, with distinct pleochroism.

Staurolite occurs in Switzerland, Germany, the former USSR, United States, Brazil, France and Scotland.

Chemical Composition: 

Aluminium iron hydroxysilicate

Crystal System / Forms: 

Orthorhombic

Hardness: 

7

Specific Gravity: 

3.72

Lustre: 

Vitreous

Refractive Index / Birefringence: 

1.74-1.75 / 0.013

Geological Occurrence: 

Switzerland, Germany, USSR, United States, Brazil, France and Scotland

Cuts & Uses: 

Baguette, Step cut, Cameo.