mineral
Quartz (or Chalcedony) Specimen
Silicon Dioxide (SiO2)
Mohs hardness of 7, vitreous to waxy luster, trigonal crystal system, conchoidal fracture, variable color from translucent white to yellowish-brown, specific gravity around 2.65.
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Physical properties
Mohs hardness of 7, vitreous to waxy luster, trigonal crystal system, conchoidal fracture, variable color from translucent white to yellowish-brown, specific gravity around 2.65.
Formation & geological history
Formed via hydrothermal activity or precipitation from silica-rich fluids filling cavities and veins within igneous, metamorphic, or sedimentary host rocks.
Uses & applications
Used in lapidary work, jewelry making, ornamental carvings, and as a collectible geological specimen.
Geological facts
Quartz is the second most abundant mineral in Earth's continental crust and comes in many varieties ranging from microcrystalline agate and jasper to macrocrystalline clear quartz crystals.
Field identification & locations
Can be identified in the field by its hardness (scratches glass and steel), lack of true cleavage, conchoidal fracture, and characteristic crystal habit or microcrystalline texture. Common worldwide in pegmatites, hydrothermal veins, and gravel deposits.
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