Hessonite



Hessonite

Striated crystals of hessonite
General
Categoryvariety of the grossular species
Chemical formulaCa3Al2Si3O12
Identification
Crystal systemcubic[1]
Cleavagenone, sometimes indistinct parting[1]
Fractureconchoidal to uneven[1]
Mohs Scale hardness7
Polish lustervitreous[1]
Optical PropertiesSingle refractive, often anomalous double refractive [1]
Birefringencenone[1]
Pleochroismnone[1]
Specific gravity3.64 to 3.69

Hessonite or Cinnamon Stone is a variety of garnet group with the general formula Ca3Al2Si3O12. The name is from the Greek hēssōn, inferior, in allusion to its lower hardness and density than most other garnet species varieties.

It has a characteristic red color, inclining to orange, much like that of gem quartz, about 7 on the mohs scale, whilst the hardness of most garnet species can reach 7.5.

Hessonite comes chiefly from Sri Lanka, where it is found generally in placer deposits, though its occurrence in its native matrix is not unknown. It is also found in Brazil and California.

References

  1. ^ a b c d e f g Gemological Institute of America, GIA Gem Reference Guide 1995, ISBN:0-87311-019-6
  • Mineral galleries
  • This article incorporates text from the Encyclopædia Britannica Eleventh Edition, a publication now in the public domain.
 
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