sedimentary
Jasper
Jasper (Silicon Dioxide, SiO2)
AI-generated identification · may be incorrectHardness: 6.5-7 (Mohs scale), Color: Reddish-brown and greenish-grey, Luster: Dull to waxy, Crystal Structure: Microcrystalline trigonal, Cleavage: None/Conchoidal fracture.
- Hardness
- 6
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Physical properties
Hardness: 6.5-7 (Mohs scale), Color: Reddish-brown and greenish-grey, Luster: Dull to waxy, Crystal Structure: Microcrystalline trigonal, Cleavage: None/Conchoidal fracture.
Formation & geological history
Formed from tiny silica-rich materials that settled in deep oceans or near volcanic activity. Over millions of years, heat and pressure consolidated these into a dense, opaque microcrystalline quartz.
Uses & applications
Commonly used in jewelry (cabochons, beads), decorative carvings, and as a popular lapidary material for hobbyists.
Geological facts
Jasper is an opaque variety of chalcedony. The red color is typically caused by iron (hematite) inclusions, while the green can result from silicate minerals or iron oxidation states.
Field identification & locations
Identify in the field by its opacity (even on thin edges), its characteristic conchoidal fracture (curved breaks), and its ability to scratch glass. Found globally in areas with ancient silica-rich deposits.
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