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Pyrope crystal
Image credit: RRUFF


A transparent, ruby-red Garnet composed of magnesium aluminum silicate where the magnesium is partially replaced with calcium and iron. The color of pyrope ranges from a deep red to almost black. Gemstone quality pyropes are mined in the Czech Republic, South Africa, and Australia.

Synonyms and Related Terms

Infrared spectrum of Pyrope
Image credit: RRUFF
Raman spectrum of pyrope
Image credit: RRUFF

garnet; Cape ruby; Arizona ruby; California ruby; Bohemian ruby; rhodolite (violet); piropo (Esp., Port.); Pyrop (Deut.); pyroop (Ned.)

Physical and Chemical Properties

  • Fracture = conchoidal
  • Luster = vitreous to resinous
  • Streak = colorless to white
  • Birefringence = isotropic
  • Pleochroism = none
  • UV fluorescence = inert
  • Composition = 3MgO-Al2O3-3SiO2
  • Mohs Hardness = 7.0 - 7.5
  • Density = 3.78 g/ml
  • Refractive Index = 1.714-1.742


Properties of Common Gemstones

Resources and Citations

  • Gem Identification Lab Manual, Gemological Institute of America, 2016.
  • Mineralogy Database: Pyrope
  • G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 354
  • Jack Odgen, Jewellery of the Ancient World, Rizzoli International Publications Inc., New York City, 1982
  • Encyclopedia Britannica, Comment: "pyrope." Accessed 14 Sept. 2001 .
  • C.W.Chesterman, K.E.Lowe, Audubon Society Field Guide to North American Rocks and Minerals, Alfred A. Knopf, New York, 1979
  • Wikipedia: (Accessed Sept. 14, 2005)
  • The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998