Phenakite

saf-ahyuh r

A rare beryllium mineral, phenakite was named in 1833 from the Greek word for "deceiver," alluding to its similar appearance to quartz. Its crystals are predominantly rhombohedral, and less commonly short and prismatic. Phenakite's rarity, hardness, lack of cleavage and high clarity make it a great option for collectors.

Phenakite Polished
Phenakite Classification
Common Name Phenakite
Species Phenakite
Phenakite Optical Properties
Transparency Transparent
Dispersion Strength: Weak Fire Value: 0.015
Refractive Index 1.654-1.670
Tolerance:(+0.026/-0.004)
Birefringence 0.016
Optic Character Uniaxial
Optic Sign Positive
Polariscope Reaction Doubly Refractive (DR)
Fluorescence SWUV: Inert to weak pink, light blue or green
LWUV: Inert to weak pink, light blue or green
Pleochroism Dichroic, weak to moderate, varying shades of body color
Phenakite Characteristic Physical Properties
Hardness 7.5-8
Streak White
Specific Gravity 2.900-3.000 Typical:2.950
Toughness Good
Luster Vitreous
Fracture Conchoidal
Cleavage Good, in one direction, Poor, in one direction
Phenakite Chemistry & Crystallography
Chemical Name beryllium silicate
Chemical Formula Be2SiO4
Crystal System Hexagonal
Chemistry Classification Silicate

Phenakite Colors

  • Colorless Phenakite Colorless
  • White Phenakite White

Alternate Names

Phenacite

Countries of Origin

Sri Lanka; Madagascar; Zambia

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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.