mineral
Jasper
Silicon dioxide (SiO2) with impurities
AI-generated identification · may be incorrectHardness 6.5-7 on Mohs scale. Opaque, massive, fine-grained variety of chalcedony. Colors vary widely but often red, yellow, brown, or green due to iron inclusions. Waxy to dull luster. No cleavage. Specific gravity 2.5-2.9.
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Physical properties
Hardness 6.5-7 on Mohs scale. Opaque, massive, fine-grained variety of chalcedony. Colors vary widely but often red, yellow, brown, or green due to iron inclusions. Waxy to dull luster. No cleavage. Specific gravity 2.5-2.9.
Formation & geological history
Forms in hydrothermal veins, volcanic rocks, and sedimentary deposits as silica-rich fluids precipitate. The red color in this specimen is typically due to iron oxide (hematite) inclusions.
Uses & applications
Used historically and currently for carving, jewelry (cabochons, beads), tumbling, and ornamental objects.
Geological facts
Jasper has been used for millennia for tools, seals, and adornment. The name means 'spotted or speckled stone'.
Field identification & locations
Identified by its opacity, hardness (can scratch glass), and conchoidal fracture. Often found as river rocks or in gravel deposits, tumbling naturally into smooth shapes like the one shown.
