Difference between revisions of "Sinhalite"

From CAMEO
Jump to navigation Jump to search
 
Line 1: Line 1:
 
== Description ==
 
== Description ==
  
A transparent, gem-quality stone.  Sinhalite was traded as [[peridot|peridot]] from Sri Lanka until 1952 when it was recognized as a unique composition by mineralogists at the British Museum.  Sinhalite is a borate mineral with formula MgAl(BO4).  Found in many colors (white, gray, pink, brown), gem quality crystals can be found in Madagascar, Tanzania and Myanmar (Burma).  
+
A transparent to translucent gem-quality stone that is a borate mineral with formula MgAl(BO4).  Sinhalite was traded as [[peridot|peridot]] from Sri Lanka until 1952 when it was recognized as a unique composition by mineralogists at the British Museum.  Sinhalite is usually a greenish to brownish yellow, but may also be found in white, gray, pink, brown colors.  Gem quality crystals have been found in Sri Lanka, Madagascar, Tanzania, and Myanmar (Burma).  
  
 +
== Physical and Chemical Properties ==
 +
 +
* Orthorhombic crystal system 
 +
* Fracture = conchoidal   
 +
* Luster = vitreous 
 +
* Streak = white 
 +
* Fluorescence = inert
 +
* Pleochroism = moderate: light brown, dark brown, and greenish brown
 +
 +
{| class="wikitable"
 +
|-
 +
! scope="row"| Mohs Hardness
 +
| 6.5 - 7.0
 +
|-
 +
! scope="row"| Density
 +
| 3.475 - 3.500 g/ml
 +
|-
 +
! scope="row"| Refractive Index
 +
| 1.668 - 1.707
 +
|-
 +
! scope="row"| Birefringence
 +
| 0.036 - 0.039
 +
|}
 
==Resources and Citations==
 
==Resources and Citations==
 
+
* Gem Identification Lab Manual, Gemological Institute of America, 2016.
 
* R.F.Symmes, T.T.Harding, Paul Taylor, ''Rocks, Fossils and Gems'', DK Publishing, Inc., New York City, 1997
 
* R.F.Symmes, T.T.Harding, Paul Taylor, ''Rocks, Fossils and Gems'', DK Publishing, Inc., New York City, 1997
 
+
* Wikipedia: [https://en.wikipedia.org/wiki/Sinhalite Sinhalite] June 2022 and Dec 2022.
* Wikipedia: [https://en.wikipedia.org/wiki/Sinhalite Sinhalite] June 2022.
 
  
 
[[Category:Materials database]]
 
[[Category:Materials database]]

Latest revision as of 14:01, 23 December 2022

Description

A transparent to translucent gem-quality stone that is a borate mineral with formula MgAl(BO4). Sinhalite was traded as Peridot from Sri Lanka until 1952 when it was recognized as a unique composition by mineralogists at the British Museum. Sinhalite is usually a greenish to brownish yellow, but may also be found in white, gray, pink, brown colors. Gem quality crystals have been found in Sri Lanka, Madagascar, Tanzania, and Myanmar (Burma).

Physical and Chemical Properties

  • Orthorhombic crystal system
  • Fracture = conchoidal
  • Luster = vitreous
  • Streak = white
  • Fluorescence = inert
  • Pleochroism = moderate: light brown, dark brown, and greenish brown
Mohs Hardness 6.5 - 7.0
Density 3.475 - 3.500 g/ml
Refractive Index 1.668 - 1.707
Birefringence 0.036 - 0.039

Resources and Citations

  • Gem Identification Lab Manual, Gemological Institute of America, 2016.
  • R.F.Symmes, T.T.Harding, Paul Taylor, Rocks, Fossils and Gems, DK Publishing, Inc., New York City, 1997
  • Wikipedia: Sinhalite June 2022 and Dec 2022.

Retrieved from "https://cameo.mfa.org/index.php?title=Sinhalite&oldid=95237"