mineral
Chalcedony
Silicon Dioxide (SiO2)
Mohs hardness of 6.5 to 7; Color ranges from white to grey, bluish, or brownish; Waxy to vitreous luster; Cryptocrystalline structure; Conchoidal fracture; Specific gravity of 2.58 to 2.64.
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Physical properties
Mohs hardness of 6.5 to 7; Color ranges from white to grey, bluish, or brownish; Waxy to vitreous luster; Cryptocrystalline structure; Conchoidal fracture; Specific gravity of 2.58 to 2.64.
Formation & geological history
Forms in hydrothermal veins or as cavity fillings in volcanic and sedimentary rocks at low temperatures from silica-rich solutions.
Uses & applications
Used for ornamental objects, carvings, lapidary work, and low-cost gemstone jewelry.
Geological facts
Chalcedony is the parent mineral species for many well-known varieties including agate, jasper, onyx, and carnelian.
Field identification & locations
Identified by its waxy luster, conchoidal fracture, and microcrystalline nature. Found worldwide in volcanic regions and weathered silica deposits.
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Limonite / Goethite (Iron Ore Mineral nodule)
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Septarian Pebble
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Schist
Schist
Metamorphic
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral