Magnesite

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Magnesite, a member of the calcite mineral group, is often found in massive form as well-formed transparent crystals are rare. Pure magnesite crystals are colorless, and any impurities present affect color, which is typically light yellow to brown or gray. Magnesite has perfect cleavage in three directions, making faceting extremely difficult. Faceted gems are often found in private collections or museums.

Magnesite Polished
Magnesite Classification
Common Name Magnesite
Species Magnesite
Magnesite Optical Properties
Transparency Transparent - Opaque
Refractive Index 1.509-1.700
Birefringence 0.191
Optic Character Uniaxial
Optic Sign Negative
Polariscope Reaction Aggregate (AGG), Doubly Refractive (DR)
Fluorescence SWUV: Inert to moderate bluish white
LWUV: Inert to moderate bluish white or yellowish white
CCF Reaction sometimes red if dyed
Pleochroism Unobservable
Magnesite Characteristic Physical Properties
Hardness 3.5-5
Streak White
Specific Gravity 3.000-3.200
Toughness Varies
Inclusions Dye, gray veining.
Luster Vitreous, Dull
Fracture Granular, Uneven
Cleavage Perfect, in one direction
Magnesite Chemistry & Crystallography
Chemical Name magnesium carbonate
Chemical Formula MgCO3
Crystal System Trigonal
Chemistry Classification Carbonate

Magnesite Colors

  • Bi-color Magnesite Bi-color
  • Yellow Magnesite Yellow
  • White Magnesite White
  • Red Magnesite Red
  • Purple Magnesite Purple
  • Pink Magnesite Pink
  • Orange Magnesite Orange
  • Multi-color Magnesite Multi-color
  • Green Magnesite Green
  • Gray Magnesite Gray
  • Brown Magnesite Brown
  • Blue Magnesite Blue
  • Black Magnesite Black

Countries of Origin

Colombia; United States of America (the); Unknown; Norway; China; Brazil; Mexico; South Africa; Thailand; India

History

Another magnificent pretender in the gemstone world, magnesite is often dyed and disguised as other stones. How versatile this porous gemstone can be! Magnesite not only takes dye well, it often has lovely veining that enhances its beauty. Magnesite is a member of the calcite mineral group and is often found in massive form. Well-formed transparent crystals are rare. Magnesite has perfect cleavage in three directions, which makes faceting extremely difficult. It is so difficult to facet that the rare, faceted stones are often found in private collections or museums. Magnesite is a 3 ½ - 4 ½ on the Mohs scale of hardness. In its natural state, magnesite is almost too soft to wear in jewelry. It's often stabilized to protect it. Whether dyed or in its natural white state, magnesite is intriguingly pretty. Contemporary stabilization processes help ensure that the color you select - and love - remains true for years to come.

Care

Wipe clean with a dry cloth and store away from other, harder stones. Do not use chemical, ultrasonic, or steam cleaners.

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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.