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Selenite is the name for transparent, colorless to near colorless crystals of gypsum, a hydrous calcium sulfate that is found in a number of forms. The name "selenite" comes from the Greek word selene, meaning "moon", no doubt in reference to the gem's white glow. Gypsum, in all varieties, is very soft and has perfect cleavage so it should be handled with care.

Selenite Polished
Selenite Classification
Common Name Selenite
Species Gypsum
Selenite Optical Properties
Transparency Translucent
Dispersion Strength: Strong Fire
Refractive Index 1.520-1.529
Birefringence 0.009-0.01
Optic Character Biaxial
Optic Sign Positive
Polariscope Reaction Aggregate (AGG), Doubly Refractive (DR)
Fluorescence SWUV: Inert to weak brownish white or greenish white
LWUV: Inert to weak brownish white or greenish white
CCF Reaction None
Pleochroism None
Selenite Characteristic Physical Properties
Hardness 1.5-2
Streak White
Specific Gravity 2.250-2.350 Typical:2.300
Toughness Poor
Luster Waxy, Pearly, Vitreous, Subvitreous
Stability Fair
Fracture Granular
Cleavage Perfect, in one direction, Good, in two directions
Selenite Chemistry & Crystallography
Chemical Name hydrous calcium sulfate
Chemical Formula CaSO4-2H2O
Crystal System Monoclinic
Chemistry Classification Sulfate

Selenite Colors

  • Black Selenite Black
  • White Selenite White
  • Colorless Selenite Colorless
  • Yellow Selenite Yellow
  • Blue Selenite Blue
  • Brown Selenite Brown
  • Pink Selenite Pink
  • Gray Selenite Gray

Countries of Origin

Canada; United States of America (the); Morocco; Unknown; Brazil; Mexico; Madagascar; Australia; Spain


Due to its soft nature selenite needs to be kept away from harder materials that will damage its surface. Selenite will turn cloudy if exposed to heat.

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Tim Matthews


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.