sedimentary
Banded Agate
Agate (Silicon Dioxide, SiO2)
AI-generated identification · may be incorrectHardness: 6.5-7 Mohs; Color: Brown, grey, white with banding; Luster: Waxy to vitreous; Crystal structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.6.
- Hardness
- 6
- Color
- Brown, grey, white with banding
- Luster
- Waxy to vitreous
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Physical properties
Hardness: 6.5-7 Mohs; Color: Brown, grey, white with banding; Luster: Waxy to vitreous; Crystal structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.6.
Formation & geological history
Formed as a secondary mineral in volcanic or metamorphic rocks, often within cavities (geodes) where silica-rich fluids deposit layers of chalcedony over time.
Uses & applications
Used in ornamental jewelry, tumbled stones, decorative carvings, and industrially for mortars and pestles due to its hardness and chemical resistance.
Geological facts
Agate is a variety of chalcedony. The name comes from the Achates River in Sicily, where agates were first discovered in ancient times.
Field identification & locations
Look for distinctive color banding and a translucent or waxy appearance. Common in riverbeds and volcanic areas across Brazil, USA, and India.
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