Pargasite

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Pargasite mostly occurs in a brown color, but has been found in greenish-brown to dark green and black. This gemstone was first found in Finland in 1814 and is named for its site of discovery. A member of the amphibole group, pargasite is closely related to hornblende. Some fine specimens of this rare gemstone have been faceted.

Pargasite Polished
Pargasite Classification
Common Name Pargasite
Species Pargasite
Pargasite Optical Properties
Transparency Transparent - Translucent
Dispersion Strength: Weak Fire
Refractive Index 1.613-1.670
Birefringence 0.020- 0.024
Optic Character Biaxial
Optic Sign Positive
Polariscope Reaction Aggregate (AGG), Doubly Refractive (DR)
Fluorescence SWUV: Inert to weak green
LWUV: Inert
Pleochroism Trichroic, (in brown gems) moderate to strong colorless, yellow, and brown; (in green gems) moderate to strong greenish yellow, green, and greenish blue
Pargasite Characteristic Physical Properties
Hardness 5-6
Streak Grayish or brownish green
Specific Gravity 3.040-3.260
Toughness Poor
Luster Vitreous
Stability Brittle
Fracture Uneven
Cleavage Perfect, in one direction
Pargasite Chemistry & Crystallography
Chemical Formula NaCa2(Mg4Al)Si6Al2O22(OH)2
Crystal System Monoclinic
Chemistry Classification Silicate

Pargasite Colors

  • Black Pargasite Black
  • Green Pargasite Green
  • Brown Pargasite Brown

Alternate Names

Pargasitic Hornblende

Countries of Origin

Tanzania, United Republic Of; Canada; Sweden; Pakistan; United States of America (the); Viet Nam; Sri Lanka; China; Australia; Chile; Ethiopia; United Kingdom of Great Britain and Northern Ireland (the)

Care

Normal care, requires gentle handling.

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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.