Pargasite Value, Price, and Jewelry Information

Home » Gemstones » Pargasite Value, Price, and Jewelry Information

Rob Lavinsky, iRocks.com – CC-BY-SA-3.0 [CC-BY-SA-3.0], via Wikimedia Commons

The amphibole group is very large and extremely complex and contains numerous distinct species that vary subtly in chemistry and physical properties. Pargasite and ferropargasite are calcic amphiboles that generally are lumped together as hornblende,even though up to 16 distinct minerals belong to this group, including actinolite. The identity of a specific amphibole is determined (ideally) by a chemical analysis or by detailed measurements of density, color, and optical data. There are undoubtedly a great many localities that could potentially yield cuttable crystals.

Pargasite Information

Data	Value
Name	Pargasite
Stone Sizes	Pargasite from Baffin Island has yielded faceted gems in the 2-3 carat range. The mineral, though abundant and widespread, seldom occurs in crystals transparent enough for cutting stones over ½ carat.
Formula	NaCa₂(Mg,Fe)₄Al(5i₆Al₂)O₂₂(OH)₂
Colors	Light brown to brown, grayish black, bluish green, dark green.
Fracture	Uneven, parting 2 directions
Hardness	5-6
Cleavage	Perfect 1 direction
Crystallography	Monoclinic; crystals prismatic, also massive, compact or granular.
Refractive Index	1.613-1.635
Birefringence	0.022
Luminescence	None.
Luminescence Present	No
Absorption Spectrum	Not diagnostic.
Pleochroism	Colorless/very light brown/light brown; colorless/bluish green/bluish green; greenish yellow/green/bluish green.
Optics	a = 1.613; β = 1.618; γ = 1.635. Biaxial (+), 2V = 120°.
Optic Sign	Biaxial +
Luster	Vitreous.
Specific Gravity	3.069-3.181
Transparency	Transparent to translucent.

See also: Actinolite; Hornblende; Amphibole; Series to Ferropargasite if Fe exceeds Mg.

Amphibole Group; closely related to Hornblende.

Optics: a=1.613; β= 1.618; γ=1.635.

Biaxial (+), 2V: 120°.

Occurrence: A widespread component of igneous and metamorphic rocks.

Pargas, Finland.

Scotland; Sweden; Russia; Austria; Venezuela.

Canada: Baffin Island, Nunavut; Nova Scotia.

United States: Fresno, California; Burlington, Pennsylvania.

Comments: The amphibole group is very large and extremely complex and contains numerous distinct species that vary subtly in chemistry and physical properties. Pargasite and ferropargasite are calcic amphiboles that generally are lumped together as hornblende, even though up to 16 distinct minerals belong to this group, including actinolite. The identity of a specific amphibole is determined (ideally) by a chemical analysis or by detailed measurements of density, color, and optical data. There are undoubtedly a great many localities that could potentially yield cuttable crystals.

Name: After the locality, Pargas, Finland.