Petalite

saf-ahyuh r

Faceted petalite gems and specimens are prized by gemstone and mineral collectors. Petalite's name is derived from the Greek petalos (leaf), referring to its perfect cleavage. Colorless material is common, and large crystals have been mined. Other petalite colors include white to yellow or gray, yellowish green to light green and pink. Crystals range from transparent to translucent and are prized for their good clarity. Faceted gems aren't often seen due to petalite's cleavage planes.

Petalite Polished
Petalite Classification
Common Name Petalite
Species Petalite
Petalite Optical Properties
Transparency Translucent-Transparent
Refractive Index 1.504-1.523 Tolerance: (+0.006/-0.002)
Birefringence 0.12-0.16
Optic Character Biaxial
Optic Sign Positive
Polariscope Reaction Doubly Refractive (DR)
Fluorescence SWUV: Inert to yellowish white
LWUV: Inert to weak orange or yellowish white
Pleochroism Unobservable
Petalite Characteristic Physical Properties
Hardness 6-6.5
Streak White
Specific Gravity 2.400-2.422 Typical:2.400
Toughness Poor
Luster Vitreous, Pearly
Fracture Subconchoidal
Cleavage Perfect, in one direction, Poor, in one direction
Petalite Chemistry & Crystallography
Chemical Name lithium aluminum silicate
Chemical Formula LiAlSi4O10
Crystal System Monoclinic
Chemistry Classification Silicate

Petalite Colors

  • Brown Petalite Brown
  • White Petalite White
  • Blue Petalite Blue
  • Colorless Petalite Colorless
  • Gray Petalite Gray
  • Yellow Petalite Yellow
  • Green Petalite Green
  • Pink Petalite Pink

Alternate Names

Castorite, Pollucite

Countries of Origin

Myanmar; Afghanistan; Angola; Czechia; Egypt; Kazakhstan; Portugal; Sweden; Mozambique; China; Russian Federation (the); Brazil; France; United Kingdom of Great Britain and Northern Ireland (the); Argentina; United States of America (the); Japan; Ukraine; Spain; Canada; Namibia; Finland; Italy; South Africa; Zimbabwe; Australia; Ethiopia

Care

Normal care for untreated material. In CVD caoated material color may be affected by polishing, recutting, ultrasonic cleaners, alcohol, and harsh chemicals.

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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.