The name of Staurolite is derived from the Greek in reference to the common twinning.  A characteristic 60 degrees cross-shape is known as Saint Andrew´s penetration twinning more rare 90 degrees cross-shape as cruciform penetration twinning. Staurolite is a typical regional metamorphic mineral of intermediate grade.

Synonyms:  Croisette, Fairy Stone
Classification:  Silicates, Nesosilicates, Staurolite Group
Chemical formula:  Fe2+2Al9Si4O23(OH)
Crystal system:  Monoclinic
Density (g/cm3):  3.74 - 3.83 measured, 3.686 calculated
Tenacity:  Brittle
Cleavage:  Distinct on {010}
Fracture:  Sub-Conchoidal
Hardness (Mohs):  7 - 7,5
Colour:  Dark brown, brownish-black, red-brown
Lustre:  Sub-Vitreous, Resinous
Streak:  White to grayish
Transparency:  Translucent



TOPGEO Mineralienhandel GmbH
Dr. Petr Zajicek
Commercial register:
HRB 671194 Amtsgericht Ulm
VAT-Id: DE147815490
Gersbach 10
74589 Satteldorf
Telephone: +49 7950 1345
Telefax: +49 7950 8483
eMail: |