sedimentary
Jasper
Microcrystalline Quartz (SiO2)
Hardness of 6.5-7 on the Mohs scale, colors vary widely (often reddish-brown, dark brown, or black with contrasting patterns due to impurities), vitreous to dull luster, cryptocrystalline structure with conchoidal fracture, and specific gravity around 2.58-2.91.
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Physical properties
Hardness of 6.5-7 on the Mohs scale, colors vary widely (often reddish-brown, dark brown, or black with contrasting patterns due to impurities), vitreous to dull luster, cryptocrystalline structure with conchoidal fracture, and specific gravity around 2.58-2.91.
Formation & geological history
Formed through the silica-rich precipitation in marine environments or hydrothermal solutions, often replacing organic material or filling cavities in volcanic rocks over millions of years.
Uses & applications
Used in ornamental carvings, cabochons, jewelry, and polished display specimens.
Geological facts
Jasper has been used since ancient times for seals, talismans, and decorative items. The name comes from the Greek word iaspe, meaning spotted stone.
Field identification & locations
Found worldwide in riverbeds, ancient marine deposits, and volcanic regions. Easily identified by its hardness, opacity, and smooth polished appearance when water-worn.
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