sedimentary
Agate
Silicon Dioxide (Chalcedony), SiO2
AI-generated identification · may be incorrectMohs hardness of 6.5 to 7; typically translucent with banding; waxy to vitreous luster; microcrystalline quartz structure.
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Physical properties
Mohs hardness of 6.5 to 7; typically translucent with banding; waxy to vitreous luster; microcrystalline quartz structure.
Formation & geological history
Forms by the deposition of silica from groundwater in cavities of igneous and sedimentary rocks over millions of years.
Uses & applications
Used extensively for ornamental objects, jewelry, and precision instruments due to its durability.
Geological facts
Agate banding represents successive layers of silica deposition, often recording ancient environmental fluctuations.
Field identification & locations
Identified by its waxy luster, conchoidal fracture, and distinct concentric banding; commonly found in volcanic rock cavities worldwide.
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