From Wikipedia, the free encyclopedia
Carnelian (also spelled cornelian) is a reddish-brown mineral which is commonly used as a semi-precious gemstone. Similar to carnelian is sard, which is generally harder and darker. (The difference is not rigidly defined, and the two names are often used interchangeably.) Both carnelian and sard are varieties of the silica mineral chalcedony colored by impurities of iron oxide. The color can vary greatly, ranging from pale orange to an intense almost-black coloration.
[edit] History
Carnelian was recovered from Bronze Age Minoan layers at Knossos on Crete in a form that demonstrated its use in decorative arts;[2] this use dates to approximately 1800 BC. Carnelian was used widely during Roman times 2000 years before the present era to make signet or seal rings for imprinting a seal with wax on correspondence or other important documents. Hot wax does not stick to Carnelian. [3] Sard was used for Assyrian cylinder seals, Egyptian and Phoenician scarabs, and early Greek and Etruscan gems.[4] The Hebrew odem (translated sardius), the first stone in the High Priest's breastplate, was a red stone, probably sard but perhaps red jasper.[4]
[edit] Etymology
The word carnelian is derived from the Latin word caro, carnis meaning flesh, in reference to the flesh color sometimes exhibited.[5] According to Pliny the Elder, sard derives its name from the city of Sardis in Lydia, but it more likely comes from the Persian word sered, meaning yellowish-red.[4]
[edit] Distinction between carnelian and sard
The names carnelian and sard are often used interchangeably, but they can also be used to describe distinct subvarieties. The general differences are as follows:[4]
| |
Carnelian |
Sard |
| Color |
Lighter, with shades ranging from orange to reddish-brown. |
Darker, with shades ranging from a deep reddish-brown to almost black. |
| Hardness |
Softer |
Harder and tougher. |
| Fracture |
Uneven, splintery and conchoidal |
Like carnelian, but duller and more hackley. |
It should be noted that all of these properties vary across a continuum, and so the boundary between carnelian and sard is inevitably blurred.
[edit] See also
[edit] References
- ^ Rudolf Duda and Lubos Rejl: Minerals of the World (Arch Cape Press, 1990)
- ^ C. Michael Hogan, Knossos fieldnotes, Modern Antiquarian (2007)
- ^ Section 12 of the translation of Weilue - a 3rd century Chinese text by John Hill under "carnelian" and note 12.12 (17)
- ^ a b c d
"Sard". Encyclopædia Britannica (11th ed.). 1911.
- ^ "Carnelian". Encyclopædia Britannica (11th ed.). 1911.
[edit] External links
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