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Etruscan Scarab
MFA# 21.1197


A translucent orange to reddish-brown form of Chalcedony. Sard is darker than Carnelian, but otherwise a similar stone. Both have been mined or gathered since at least 3000 BCE. Water-worn pebbles of sard are found in Egypt, India, and several areas of Europe. It was popular for amulets and scarabs.

Oval gem
MFA# 13.237

Synonyms and Related Terms

chalcedony; carnelian; sardius; sardoine; sardine

Physical and Chemical Properties

  • No visible crystals
  • Fracture = conchoidal, uneven, splintery
  • Luster = waxy to vitreous
  • Streak = white
  • Fluorescence = generally inert
  • Pleochroism = absent
Composition SiO2
Mohs Hardness 6.5-7.0
Density 2.59-2.61 g/ml
Refractive index 1.535 - 1.539
Birefringence 0.003 - 0.009


Properties of Common Gemstones

Resources and Citations

  • Gem Identification Lab Manual, Gemological Institute of America, 2016.
  • Mineralogy Database: Quartz
  • Jack Odgen, Jewellery of the Ancient World, Rizzoli International Publications Inc., New York City, 1982
  • A.Lucas, J.R.Harris, Ancient Egyptian Materials and Industries, Edward Arnold Publishers Ltd., London, 4th edition, 1962
  • C.W.Chesterman, K.E.Lowe, Audubon Society Field Guide to North American Rocks and Minerals, Alfred A. Knopf, New York, 1979
  • Wikipedia: Carnelian (Accessed Nov. 9, 2005 and Dec 2022)
  • G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 22
  • Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997
  • The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998