sedimentary
Agate
Silicon dioxide (chalcedony), SiO2
AI-generated identification · may be incorrectHardness of 6.5 to 7 on the Mohs scale, waxy luster, microcrystalline crystal structure, and exhibits conchoidal fracture.
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Physical properties
Hardness of 6.5 to 7 on the Mohs scale, waxy luster, microcrystalline crystal structure, and exhibits conchoidal fracture.
Formation & geological history
Formed by the deposition of silica from groundwater in cavities of igneous or sedimentary rocks over millions of years.
Uses & applications
Used primarily in jewelry, ornamental carvings, and precision instruments due to its durability.
Geological facts
Agates often display distinct concentric banding patterns formed in stages as silica solutions fill hollow cavities.
Field identification & locations
Identify by its waxy luster, translucent layers, and resistance to scratching by steel; commonly found in volcanic rock cavities worldwide.
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Sandstone or Siltstone
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