mineral
Chalcedony
Silicon dioxide (SiO2)
AI-generated identification · may be incorrectMohs hardness of 6.5 to 7; vitreous to waxy luster; cryptocrystalline structure; white, gray, or brownish color; conchoidal fracture.
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Physical properties
Mohs hardness of 6.5 to 7; vitreous to waxy luster; cryptocrystalline structure; white, gray, or brownish color; conchoidal fracture.
Formation & geological history
Forms in low-temperature hydrothermal environments, filling cavities in volcanic and sedimentary rocks.
Uses & applications
Used in ornamental carvings, lapidary arts, metaphysical collections, and occasionally low-cost jewelry.
Geological facts
Chalcedony is the microcrystalline parent material for many gemstones including jasper, agate, and onyx.
Field identification & locations
Identify by its waxy luster and lack of visible crystal grains; found worldwide in volcanic cavities.
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Other mineral specimens
Gneiss or Schist
Gneiss or Mica Schist with Garnet
Metamorphic
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Tumbled granite
Granite, a coarse-grained felsic intrusive igneous rock
igneous
Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
igneous
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Granite
Granite (Phaneritic intrusive igneous rock)
igneous