mineral
Chalcedony (Agate)
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectHardness of 6.5–7 on the Mohs scale with a waxy to vitreous luster. Displays a translucent grayish to tan body with a cryptocrystalline structure and conchoidal fracture.
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Physical properties
Hardness of 6.5–7 on the Mohs scale with a waxy to vitreous luster. Displays a translucent grayish to tan body with a cryptocrystalline structure and conchoidal fracture.
Formation & geological history
Formed by precipitation of silica from low-temperature aqueous fluids in cavities of volcanic and sedimentary rocks.
Uses & applications
Commonly polished into cabochons, beads, and carvings for jewelry or lapidary display.
Geological facts
Chalcedony has been used since the Bronze Age to carve intaglios and cylinder seals due to its toughness and resistance to splintering.
Field identification & locations
Identified by its waxy luster, hardness (scratches glass), and translucent microcrystalline texture; found abundantly worldwide in volcanic regions.
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Metamorphic
Sandstone (with potential mineral staining/concretions)
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Tumbled granite
Granite, a coarse-grained felsic intrusive igneous rock
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Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
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Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Granite
Granite (Phaneritic intrusive igneous rock)
igneous