Dumortierite

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A mineral that often forms as an inclusion in quartz, dumortierite is a mineral that is often fashioned as cabochons or beads for jewelry. While prized for its deep violet to blue colors, it may also be found in shades of pink, gray and brown. Named for French paleontologist Eugne Dumortier, dumortierite is an exotic gem that is durable, untreated and rare.

Dumortierite Polished
Dumortierite Classification
Common Name Dumortierite
Species Dumortierite
Dumortierite Optical Properties
Transparency Translucent - Opaque
Dispersion Strength: None
Refractive Index 1.678-1.689
Birefringence 0.015-0.037
Optic Character Biaxial
Optic Sign Negative
Polariscope Reaction Aggregate (AGG), Doubly Refractive (DR)
Fluorescence SWUV: Moderate bluish white
LWUV: Inert to yellowish white or red
Pleochroism Unobservable
Dumortierite Characteristic Physical Properties
Hardness 7-8.5
Streak White
Specific Gravity 3.260-3.410
Inclusions Dumortierite is most common in its fibrous or granular structured variety.
Luster Vitreous
Fracture Conchoidal
Cleavage Good, in one direction, Poor, in one direction
Dumortierite Chemistry & Crystallography
Chemical Formula Al7(BO3)(SiO4)3O3
Crystal System Orthorhombic
Chemistry Classification Silicate

Dumortierite Colors

  • Pink Dumortierite Pink
  • Purple Dumortierite Purple
  • Multi-color Dumortierite Multi-color
  • Blue Dumortierite Blue
  • Brown Dumortierite Brown

Alternate Names

Dumortierite Quartz

Countries of Origin

Canada; China; Brazil; South Africa

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Tim Matthews

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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.