mineral
Grey Agate
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Hardness: 6.5-7 on Mohs scale; Color: translucent grey to brownish-grey with subtle banding; Luster: vitreous to waxy when polished; Crystal Structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.58-2.64.
- Hardness
- 6
- Color
- translucent grey to brownish-grey with subtle banding
- Luster
- vitreous to waxy when polished
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Physical properties
Hardness: 6.5-7 on Mohs scale; Color: translucent grey to brownish-grey with subtle banding; Luster: vitreous to waxy when polished; Crystal Structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.58-2.64.
Formation & geological history
Formed primarily in volcanic gas cavities (vesicles) through the deposition of silica-rich hydrothermal fluids over long periods.
Uses & applications
Popular for lapidary work, jewelry making (cabochons, beads), decorative tumbled stones, and rock collections.
Geological facts
Agate is a variety of chalcedony characterized by its fine grain and brightness of color. Grey agate is often used as a grounding stone in crystal healing practices.
Field identification & locations
Identified by its waxy luster, smooth translucent body, and subtle internal banding. Commonly found in Brazil, Uruguay, Madagascar, and the United States.
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