gemstone
Agate
Silicon Dioxide (Chalcedony), SiO2
Hardness of 6.5 to 7 on the Mohs scale, waxy to vitreous luster, conchoidal fracture, variable translucent to opaque colors including brown, grey, and purple.
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Physical properties
Hardness of 6.5 to 7 on the Mohs scale, waxy to vitreous luster, conchoidal fracture, variable translucent to opaque colors including brown, grey, and purple.
Formation & geological history
Formed primarily within the cavities of volcanic and metamorphic rocks through the slow deposition of silica-rich groundwater over millions of years.
Uses & applications
Used extensively in jewelry, ornamental carvings, lapidary art, and precision instruments due to its durability.
Geological facts
Agate bands represent successive layers of deposition in a cavity. It is named after the Achates River in Sicily.
Field identification & locations
Identified by its waxy luster, conchoidal fracture, and sometimes banded patterns. Commonly found in gravel beds, volcanic regions, and riverbeds worldwide.
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