sedimentary
Chert (Jasper)
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectHardness: 6.5-7 Mohs; Color: Red, white, and tan; Luster: Waxy to dull; Crystal structure: Cryptocrystalline (Trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.65
- Hardness
- 6
- Color
- Red, white, and tan
- Luster
- Waxy to dull
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Physical properties
Hardness: 6.5-7 Mohs; Color: Red, white, and tan; Luster: Waxy to dull; Crystal structure: Cryptocrystalline (Trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.65
Formation & geological history
Formed through the accumulation of silica-rich microfossils (like radiolaria or diatoms) or by chemical precipitation from hydrothermal fluids in volcanic or sedimentary environments.
Uses & applications
Historically used for making stone tools (arrowheads); currently used in jewelry (cabochons), as an ornamental stone, and in lapidary arts.
Geological facts
Red jasper specifically gets its color from iron inclusions. It has been used for millennia by cultures globally for both practical tools and spiritual amulets.
Field identification & locations
Identify by its waxy luster, smoothness to the touch, and distinct shell-like (conchoidal) fractures. Common in riverbeds, desert regions, and areas with ancient seafloor activity.
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