sedimentary
Botryoidal Agate
Silicon Dioxide (Chalcedony), SiO2
AI-generated identification · may be incorrectHardness of 6.5 to 7 on the Mohs scale, reddish-brown color, waxy to vitreous luster, and a microcrystalline or cryptocrystalline structure with globular, grape-like habit.
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Physical properties
Hardness of 6.5 to 7 on the Mohs scale, reddish-brown color, waxy to vitreous luster, and a microcrystalline or cryptocrystalline structure with globular, grape-like habit.
Formation & geological history
Formed through the deposition of silica-rich groundwater in cavities of volcanic or sedimentary rocks over millions of years.
Uses & applications
Used primarily in lapidary arts, gemstone jewelry carving, and as prized specimens for mineral collectors.
Geological facts
The distinctive grape-like or rounded bubbly shape is known as a botryoidal habit, formed as chalcedony layers accumulated in concentric spheres.
Field identification & locations
Identified by its bulbous surface texture, conchoidal fracture, and resistance to steel. Commonly sourced from regions with volcanic activity such as Brazil, India, and the western United States.
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