Sard
Description
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.
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 |
Comparisons
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