mineral
Chalcedony
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectHardness: 6.5-7 on the Mohs scale, Color: Various shades of blue, grey, white, or multicolored, Luster: Waxy to vitreous, Crystal structure: Trigonal (microcrystalline quartz/moganite mixture), Cleavage: None, Specific gravity: 2.58-2.64
- Hardness
- 6
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Physical properties
Hardness: 6.5-7 on the Mohs scale, Color: Various shades of blue, grey, white, or multicolored, Luster: Waxy to vitreous, Crystal structure: Trigonal (microcrystalline quartz/moganite mixture), Cleavage: None, Specific gravity: 2.58-2.64
Formation & geological history
Forms in low-temperature hydrothermal environments, filling cavities in volcanic or sedimentary rocks through the deposition of silica-rich solutions over millions of years.
Uses & applications
Used in ornamental carvings, lapidary arts, jewelry, and as a collectible mineral specimen.
Geological facts
Chalcedony has been used since antiquity to create intaglios, seals, and precious gemstones due to its fine grain and durability.
Field identification & locations
Can be identified by its distinctive waxy luster, microcrystalline texture, and botryoidal or crusting habit lining cavities. Commonly found worldwide in volcanic rock vesicles.
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Gneiss or Schist
Gneiss or Mica Schist with Garnet
Metamorphic
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
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Granite
Granite (Phaneritic intrusive igneous rock)
igneous
Septarian Pebble
Septarian nodule / Concretion
sedimentary