sedimentary
Jasper
Silicon Dioxide (Microcrystalline Quartz, SiO2)
Hardness of 6.5 to 7 on the Mohs scale, typically reddish-brown in color due to iron inclusions, vitreous to dull luster, cryptocrystalline or microcrystalline structure with no visible cleavage, and a specific gravity of around 2.65.
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Physical properties
Hardness of 6.5 to 7 on the Mohs scale, typically reddish-brown in color due to iron inclusions, vitreous to dull luster, cryptocrystalline or microcrystalline structure with no visible cleavage, and a specific gravity of around 2.65.
Formation & geological history
Formed through the silica-rich precipitation in marine environments or the silicification of organic or sedimentary materials, often occurring during hydrothermal activity or diagenesis, with geological ages spanning from the Precambrian to recent times.
Uses & applications
Commonly used for ornamental carvings, cabochons in jewelry, spheres, and as a polished collector's specimen.
Geological facts
Jasper has been used since ancient times for seals, signet rings, and talismans by various civilizations including the ancient Greeks, Romans, and Egyptians.
Field identification & locations
Easily identified by its opaque nature, conchoidal fracture, hardness that scratches glass, and distinctive reddish-brown coloration from iron oxide. Found worldwide in riverbeds, beaches, and mountainous regions.
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