sedimentary
Agate
Silicon dioxide (chalcedony variety), SiO2
AI-generated identification · may be incorrectHardness of 6.5 to 7 on the Mohs scale, waxy luster, and cryptocrystalline structure with variable translucent banding colors.
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Physical properties
Hardness of 6.5 to 7 on the Mohs scale, waxy luster, and cryptocrystalline structure with variable translucent banding colors.
Formation & geological history
Formed through the deposition of silica-rich groundwater within cavities of ancient volcanic and metamorphic rocks over millions of years.
Uses & applications
Widely utilized for ornamental jewelry, decorative carvings, and as a popular specimen for rock tumbling and mineral collecting.
Geological facts
Agate was historically prized by ancient civilizations for protective amulets and carved intaglio seals.
Field identification & locations
Easily identified by its distinctive concentric color banding and conchoidal fracture, commonly found globally in ancient volcanic deposits and river gravels.
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