sedimentary
Red Jasper (Siltstone variant)
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Hardness: 6.5-7 (Mohs scale), Color: Brick red to brownish-red, Luster: Dull/waxy, Crystal structure: Microcrystalline (trigonal), Cleavage: None (conchoidal fracture), Specific Gravity: 2.5-2.9.
- Hardness
- 6
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Physical properties
Hardness: 6.5-7 (Mohs scale), Color: Brick red to brownish-red, Luster: Dull/waxy, Crystal structure: Microcrystalline (trigonal), Cleavage: None (conchoidal fracture), Specific Gravity: 2.5-2.9.
Formation & geological history
Formed from silica-rich fluids permeating through microcrystalline sedimentary deposits. The red color is derived from iron impurities oxidized during the burial and lithification process.
Uses & applications
Commonly used for lapidary work, jewelry (cabochons), ornamental carvings, and as a collector's stone. Historically used for making tools and seals.
Geological facts
Jasper was a favorite gem in the ancient world; its name can be traced back in Arabic, Persian, Greek, and Latin. It is known as the 'supreme nurturer' in metaphysical circles.
Field identification & locations
Identify in the field by its opaque nature (even on thin edges), its hardness (will scratch glass), and its distinctive dull, waxy luster when wet. Often found in riverbeds and alluvial deposits alongside quartz and chalcedony.
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