Alabaster

saf-ahyuh r

Alabaster is a fine-grained massive form of gypsum. Alabaster ranges from white to yellow, pink, and brown. Due to its porosity it is often dyed. It has been used for centuries for statues, carvings, and other ornamental purposes. Treated alabaster is used as a marble simulant. Due to its extreme softness, it is ideal for fashioning into works of art.

Alabaster Classification
Common Name Alabaster
Species Gypsum
Alabaster Optical Properties
Transparency Translucent - Opaque
Refractive Index 1.520-1.529
Tolerance:(+0.001/-0.001)
Birefringence 0.009- 0.010
Optic Character Biaxial
Optic Sign Positive
Polariscope Reaction Aggregate (AGG), Doubly Refractive (DR)
Fluorescence SWUV: Inert to weak brownish to greenish white
LWUV: Inert to weak brownish to greenish white
Pleochroism None
Alabaster Characteristic Physical Properties
Hardness 1.5-2
Streak White
Specific Gravity 2.250-2.350 Typical:2.300
Toughness Poor
Inclusions Alabaster is sometimes banded, veined,or patterned like marble and it is often dyed and has a poor polish.
Luster Waxy, Subvitreous
Stability Fair
Fracture Granular
Cleavage None
Alabaster Chemistry & Crystallography
Chemical Name hydrous calcium sulfate
Chemical Formula CaSO4-2H2O
Crystal System Monoclinic
Chemistry Classification Sulfate

Alabaster Colors

  • Pink Alabaster Pink
  • White Alabaster White
  • Brown Alabaster Brown

Alternate Names

Alabastrite

Care

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

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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.