CORNELIAN

'Cornelian' is a red variety of chalcedony, which is cryptocrystalline quartz. Its red colour is due to the presence of iron impurities in the form of iron oxide or hematite. It can vary from a flesh red to a clear red. It is usually cut en cabochon, or into beads, and is also used for intaglios and cameos. Imitations of cornelian are made by the staining of agate. Cornelian is related to amethyst and citrine.

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Sources

Technical Details

Sources

Originally found in the deserts of Arabia and Egypt, it has also been found in the Rio Grande area, India, China, Colombia, Saxony, Scotland, West Germany, and the USA.Hello

Technical Details

★ Chemical composition and name: SiO₂ / Silicon Dioxide

★ Hardness : 7

★ Specific Gravity : 2.65 - 2.66

★ Refractive Index (R.I.): 1.543 - 1.552 to 1.545 - 1.554

★ Bi-refringence : 0.009

★ Optic Sign : Positive

★ Optical Character : Uniaxial