Sardonyx

Layered onyx
MFA# 99.101

Description

A type of onyx, which is an Agate with parallel bands. Sardonyx has layers of brownish sard (red carnelian) alternating with lighter-color layers of onyx. Often used as a gemstone, it has been mined or gathered since before 2200 BCE.

Synonyms and Related Terms

onyx; quartz; agate; chalcedony

Sardonyx seal
MFA# 01.7550

Physical and Chemical Properties

• Fracture = conchoidal.
• Luster = vitreous to waxy.
• Streak = white.
• Mohs Hardness = 7.0
• Density = 2.6 g/ml

Comparisons

Properties of Common Gemstones

Resources and Citations

• Mineralogy Database: Quartz

• Jack Odgen, Jewellery of the Ancient World, Rizzoli International Publications Inc., New York City, 1982

• Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976

• A.Lucas, J.R.Harris, Ancient Egyptian Materials and Industries, Edward Arnold Publishers Ltd., London, 4th edition, 1962

• The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998

• C.W.Chesterman, K.E.Lowe, Audubon Society Field Guide to North American Rocks and Minerals, Alfred A. Knopf, New York, 1979