Staurolite

saf-ahyuh r

The name staurolite comes from the Greek word stauros, meaning cross. Staurolite is prized for its twinned crystals that intersect at 60 or 90 angles forming x-like or perpendicular crosses and specimens exhibiting these forms are highly prized by collectors. Sometimes referred to respectively as St. Andrew's and Greek crosses as well as lucky cross, fairy stone or fairy cross, one legend says the crystal crosses were created by the tears of fairies whom could not help but cry when they heard of Christ's crucifixion. Staurolite is a metamorphic mineral that ranges from translucent to opaque in appearance and facetable gems are vary rare.

Staurolite Polished
Staurolite Classification
Common Name Staurolite
Species Staurolite
Staurolite Optical Properties
Transparency Opaque-Translucent
Dispersion Strength: Moderate Fire Value: 0.021
Refractive Index 1.736-1.762 Tolerance: (+0.015/-0.015)
Birefringence 0.009-0.015
Optic Character Biaxial
Optic Sign Positive
Polariscope Reaction Doubly Refractive (DR)
Fluorescence SWUV: Inert
LWUV: Inert
CCF Reaction None
Pleochroism Trichroic, moderate yellow to red, brownish yellow, and dark red
Staurolite Characteristic Physical Properties
Hardness 7-7.5
Streak White
Specific Gravity 3.650-3.790 Typical:3.710
Toughness Good
Luster Vitreous, Resinous
Fracture Conchoidal, Uneven
Cleavage Good, in one direction
Staurolite Chemistry & Crystallography
Chemical Name iron aluminum silicate hydroxide
Chemical Formula (Fe,Mg,Zn)2Al9(Si,Al)4O22(OH)2
Crystal System Monoclinic
Chemistry Classification Silicate

Staurolite Colors

  • Blue Staurolite Blue
  • Multi-color Staurolite Multi-color
  • Brown Staurolite Brown
  • Black Staurolite Black
  • Colorless Staurolite Colorless
  • Red Staurolite Red
  • Yellow Staurolite Yellow

Alternate Names

Cross Stones, Fairy Crosses, Lucky Cross

Countries of Origin

Austria; Sweden; United States of America (the); Unknown; Russian Federation (the); Brazil; Madagascar; France; Portugal; Germany; Spain

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Species/Variety

Staurolite (twinned)

The name staurolite comes from the Greek word stauros, meaning cross. Staurolite is prized for its twinned crystals that intersect at 60 or 90 angles forming x-like or perpendicular crosses and specimens exhibiting these forms are highly prized by collectors. Sometimes referred to respectively as St. Andrew's and Greek crosses as well as lucky cross, fairy stone or fairy cross, one legend says the crystal crosses were created by the tears of fairies whom could not help but cry when they heard of Christ's crucifixion. Staurolite is a metamorphic mineral that ranges from translucent to opaque in appearance and facetable gems are vary rare.

Staurolite (twinned) Staurolite
Staurolite (twinned) Classification
Common Name Staurolite (twinned)
Staurolite (twinned) Optical Properties
Pleochroism Unobservable
Tim Matthews

Author

Tim Matthews

Tim Matthews is President and Chief Executive Officer of Jewelry Television® (JTV), as well as a member of the company's Board of Directors. He oversees and leads all aspects of the company's powerful omni-digital retail platform that uniquely specializes in fine jewelry and gemstones. His passion for business and gemstones has led him to become a recognized expert in the field of gemology. He is a life member of the Gemmological Association of Great Britain (Gem-A) and has earned Gem-A's highest degrees, the Gemmology (FGA) and Diamond (DGA) diplomas. He is also a Graduate Gemologist (GG) of the Gemological Institute of America (GIA) and has also completed GIA's Graduate Diplomas in Diamonds, Colored Stones and Pearls. Under his leadership, JTV has become the leader in the sourcing and selling of color gemstones and jewelry.

This page was created on June 27, 2014.

This page was last edited on October 24, 2019.