Epidote

saf-ahyuh r

A pearly transparent to nearly opaque gemstone, Epidote often has a yellowish-green or green "pistachio" color. Small faceted stones may appear black due to the dark nature of the colors. Epidote specimens are often appreciated for their dramatic crystal displays.

Epidote Polished
Epidote Classification
Common Name Epidote
Species Epidote
Epidote Optical Properties
Transparency Transparent - Translucent
Dispersion Strength: Strong Fire Value: 0.030
Refractive Index 1.729-1.768
Tolerance:(+0.012/-0.035)
Birefringence 0.019-0.045
Optic Character Biaxial
Optic Sign Negative
Polariscope Reaction Doubly Refractive (DR)
Fluorescence SWUV: inert
LWUV: inert
Pleochroism Trichroic, strong green, brown, and yellow
Epidote Characteristic Physical Properties
Hardness 6-7
Streak Gray
Specific Gravity 3.350-3.500 Typical:3.400
Toughness Varies
Luster Vitreous, Greasy
Fracture Conchoidal, Uneven
Cleavage Perfect, in one direction, Good, in one direction
Epidote Chemistry & Crystallography
Chemical Name calcium aluminum iron silicate
Chemical Formula Ca2(Al,Fe)3(SiO4)3(OH)
Crystal System Monoclinic
Chemistry Classification Silicate

Epidote Colors

  • Brown Epidote Brown
  • Yellow Epidote Yellow
  • Green Epidote Green
  • Black Epidote Black

Epidote Spectra

Epidote Spectra
EPIDOTE. (Unpolarized)

Color due to iron and manganese. The intense absorption up to 500nm. in this rare red variety of epidote masks any evidence of the iron band normally detected in the pale greenish brown stones centered at 455nm. often accompanied by a weaker band at 475nm. However, in this red specimen a fairly wide band appears centered at 550nm

Epidote Spectra
EPIDOTE. (Lighter γ ray)

Color due to iron and manganese. The intense absorption up to 500nm. in this rare red variety of epidote masks any evidence of the iron band normally detected in the pale greenish brown stones centered at 455nm. often accompanied by a weaker band at 475nm. However, in this red specimen a fairly wide band appears centered at 550nm. When the lighter gamma ray is isolated the much weaker absorption in the green is evidence of the lighter color in the pleochroic effect

Epidote Spectra
EPIDOTE

Color due to iron. This strongly pleochroic dark brown gemstone may require the use of a polarizing filter to transmit sufficient light from the lighter brown alpha ray. The main feature is a strong band centered at 458nm. in the deep blue with a weaker one on the long wave side at 475nm. which strengthens as the greenish beta ray is located. The darker brown gamma ray can absorb all up to about 500nm. and may obscure the bands referred to here.

Jewelry Television acknowledges the significant scientific contributions of John S Harris, FGA to the study of gemstone spectra and with deep appreciation to him, acknowledges the use of his images and related notes about gemstones and their spectra in the educational materials on this website.

Alternate Names

Pistacite- Yellow Green

Countries of Origin

Afghanistan; Pakistan; United States of America (the); Unknown; China; Brazil; Mexico

Shop Epidote

Sisk Gemology Reference

Showcasing 200 gemstones in over 1,000 pages and accompanied by more than 2,000 photos, The Sisk Gemology Reference is a must-have in every collector’s library. Each comprehensive, three-volume set features state-of-the-art photography, detailed illustrations, and scientifically precise descriptions to create an entrancing experience for gemstone amateurs and afficionados alike.

Shop Now

 
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.