Sinhalite

saf-ahyuh r

Sinhalite is named after its discovery location, Sri Lanka, using its Sanskrit name, Sinhala. This rare gemstone was, until recently, only found in Sri Lanka, but is now mined in Tanzania, Madagascar and Burma. Often occurring in green to brown to brownish black hues, it was once mistakenly believed to be a variety of olivine.

Sinhalite Polished
Sinhalite Classification
Common Name Sinhalite
Species Sinhalite
Sinhalite Optical Properties
Transparency Transparent - Translucent
Dispersion Strength: Moderate Fire Value: 0.017
Refractive Index 1.668-1.707
Tolerance:(+0.005/-0.003)
Birefringence 0.036-0.039
Optic Character Biaxial
Optic Sign Negative
Polariscope Reaction Doubly Refractive (DR)
Fluorescence SWUV: Inert
LWUV: Inert
Pleochroism Trichroic, moderate to strong light brown, dark brown, and greenish brown
Sinhalite Characteristic Physical Properties
Hardness 6.5-7
Streak White
Specific Gravity 3.460-3.500 Typical:3.480
Toughness Good
Inclusions Sinhalite might have natural inclusions, sillimanite needles and can show iron staining.
Luster Vitreous
Fracture Conchoidal
Cleavage None
Sinhalite Chemistry & Crystallography
Chemical Name magnesium aluminum iron borate
Chemical Formula MgAlBO4
Crystal System Orthorhombic
Chemistry Classification Borate

Sinhalite Colors

  • Green Sinhalite Green
  • Yellow Sinhalite Yellow

Sinhalite Spectra

Sinhalite Spectra
SINHALITE

Color due to iron. In this large dark reddish brown sinhalite of 31cts it is possible to detect the weak band centered at 526nm. As with most dark brown stones, absorption in the deep blue to violet is strong which here is up to about 480nm. Only one of the four lines usually present in this area is captured on camera at 493nm.

Sinhalite Spectra
SINHALITE

Color due to iron. Four bands can be resolved at 452nm. 463nm. (broadest) 475nm. and 493nm. Another vague line may be detected in darker brown Sinhalite at 526nm. but is not seen 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.

Countries of Origin

Sri Lanka; India

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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.