sedimentary
Agate
Silicon Dioxide (Chalcedony), SiO2
AI-generated identification · may be incorrectHardness of 6.5 to 7 on the Mohs scale, waxy to vitreous luster, cryptocrystalline structure, conchoidal fracture, and specific gravity of 2.60 to 2.65.
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Physical properties
Hardness of 6.5 to 7 on the Mohs scale, waxy to vitreous luster, cryptocrystalline structure, conchoidal fracture, and specific gravity of 2.60 to 2.65.
Formation & geological history
Formed by the deposition of silica from groundwater in the cavities of igneous and sedimentary rocks, often over millions of years.
Uses & applications
Used primarily for making ornamental jewelry, carvings, beads, and as collectible lapidary specimens.
Geological facts
Agates often display distinct concentric banding patterns formed by alternating layers of chalcedony and quartz in varying colors.
Field identification & locations
Identified by its microcrystalline texture, distinct banding, and resistance to scratching by steel. Commonly found worldwide in volcanic rock cavities and riverbeds.
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