sedimentary
Jasper
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Hardness of 6.5 to 7 on the Mohs scale, red to reddish-brown color, waxy to dull luster, cryptocrystalline or microcrystalline crystal structure, conchoidal fracture with no true cleavage, specific gravity of 2.58 to 2.91.
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Physical properties
Hardness of 6.5 to 7 on the Mohs scale, red to reddish-brown color, waxy to dull luster, cryptocrystalline or microcrystalline crystal structure, conchoidal fracture with no true cleavage, specific gravity of 2.58 to 2.91.
Formation & geological history
Formed through the precipitation of silica-rich fluids in sedimentary environments, often involving the alteration of silica-rich ash or chemical precipitation in marine basins. Can be millions to billions of years old.
Uses & applications
Used in ornamental carvings, cabochons, jewelry, decorative objects, and as a popular specimen for rock collectors.
Geological facts
Jasper has been used by ancient civilizations since antiquity for tools, seals, and amulets. Its red color typically comes from iron oxide inclusions within the microcrystalline quartz matrix.
Field identification & locations
Can be identified in the field by its hardness (scratches glass), waxy luster, lack of cleavage, and opaque reddish coloration. Commonly found in riverbeds, coastal areas, and ancient sedimentary formations worldwide.
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