sedimentary
Agate
Silicon Dioxide (Chalcedony), SiO2
Hardness of 6.5-7 on the Mohs scale, waxy luster, crypto-crystalline structure, conchoidal fracture, colors include white, gray, brown, and various bands.
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Physical properties
Hardness of 6.5-7 on the Mohs scale, waxy luster, crypto-crystalline structure, conchoidal fracture, colors include white, gray, brown, and various bands.
Formation & geological history
Formed by the deposition of silica from groundwater in the cavities of igneous and sedimentary rocks, often developing concentric bands over millions of years.
Uses & applications
Used in jewelry, decorative carvings, ornaments, and occasionally in industrial applications requiring wear-resistant bearings.
Geological facts
Agate is one of the most popular stones used in art and healing since ancient times, named after the Achates River in Sicily.
Field identification & locations
Easily identified by its distinctive banded patterns and waxy luster; commonly found worldwide in volcanic rock cavities or weathered stream gravels.
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