sedimentary
Jasper
Microcrystalline quartz (SiO2)
AI-generated identification · may be incorrectHardness of 6.5 to 7 on the Mohs scale, reddish-brown color from iron impurities, dull to vitreous luster, and a cryptocrystalline structure with conchoidal fracture.
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Physical properties
Hardness of 6.5 to 7 on the Mohs scale, reddish-brown color from iron impurities, dull to vitreous luster, and a cryptocrystalline structure with conchoidal fracture.
Formation & geological history
Formed through the silification of sedimentary or volcanic deposits, often precipitating from silica-rich hydrothermal fluids over millions of years.
Uses & applications
Widely used for ornamental carvings, polished cabochons in jewelry, and as a decorative landscaping stone.
Geological facts
Jasper has been used since antiquity for talismans, seals, and weaponry like arrowheads due to its toughness and ability to take a high polish.
Field identification & locations
Easily identified in the field by its opaque red-brown coloration, smooth water-worn surfaces in riverbeds, and lack of visible crystal grains. Commonly found globally in stream gravels and ancient seabeds.
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