mineral
Jasper
Microcrystalline Quartz (SiO2)
AI-generated identification · may be incorrectHardness: 6.5-7 (Mohs scale), Color: primarily brown, yellow, or red due to iron oxide impurities, Luster: dull to vitreous, Crystal structure: trigonal (microcrystalline), Cleavage: none, Specific gravity: 2.5-2.9
- Hardness
- 6
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Physical properties
Hardness: 6.5-7 (Mohs scale), Color: primarily brown, yellow, or red due to iron oxide impurities, Luster: dull to vitreous, Crystal structure: trigonal (microcrystalline), Cleavage: none, Specific gravity: 2.5-2.9
Formation & geological history
Forms as a precipitate in silica-rich fluids, often associated with volcanic activity or hydrothermal veins. Can also form in sedimentary environments from silica-rich groundwater.
Uses & applications
Used primarily as an ornamental stone, for tumbling, lapidary work, and sometimes in jewelry.
Geological facts
Jasper is an opaque variety of chalcedony. The name means 'spotted or speckled stone'. The brown color in this piece is likely due to goethite or limonite inclusions.
Field identification & locations
Identify by its hardness (scratches glass), opacity, and conchoidal fracture. Often found as river rocks or in gravel deposits, as seen in the background.
