Glittering Stones >> Semi Precious Stones >> Chalcedony
Semi Precious Stone Chalcedony
Chalcedony is defined as a fibrous cryptocrystalline form of silica and composing a variety of mineral Quartz and moganite with a trigonal crystal structure. The chalcedony mineral has waxy luster and it may be semitransparent or translucent.
The varieties of chalcedony are agate, carnelian, chrysoprase, heliotrope and moss agate. The structure of Chalcedony was cryptocrystalline quartz and also composes of monoclinic polymorph of quartz called moganite. The Mohs scale hardness for the mineral is 6 to 7.5 with waxy luster. It is a more soluble mineral compared to quartz under low temperature condition, despite of its two mineral chemical identical. Wide range of colors are available in Chalcedony, but commonly seen colors are white to gray, grayish blue or shades of brown ranging from pale to nearby black.
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Historical Facts of Chalcedony
| Refractive Index |
1.530 - 1.539 |
| Chemical Composition |
SiO2 |
| Hardness |
6 - 7 |
| Density |
2.59 - 2.61 |
| Crystal Group |
Hexagonal |
| Crystal system |
Trigonal |
| Luster |
Waxy, Vitreous, Dull, Greasy, Silky |
| Other names |
Chalcedon, Calcedonia, Calcédoine |
| Varieties |
Agate, Carnelian, Chrysoprase, Heliotrope, Moss agate |
| Color |
White, Gray, Grayish blue, Brown, Pale black, Green, Blue, Lavender |
| Ocurrence |
Brazil, Afghanistan, U.SA. Germany, India, Uruguay, Austarlia, Egypt, Italy, Scotland, South Africa, Namibia, Madagascar |
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Gem Chalcedony Jewelry
Chalcedony Bracelet  |
Chalcedony Earrings  |
Chalcedony Necklace  |
Chalcedony Ring  |
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