sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Hardness: 6.5-7 (Mohs scale), Color: Deep red to reddish-brown with banding, Luster: Dull to vitreous, Crystal structure: Microcrystalline (Trigonal), Cleavage: None (conchoidal fracture), Specific Gravity: 2.58-2.91
- Hardness
- 6
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Physical properties
Hardness: 6.5-7 (Mohs scale), Color: Deep red to reddish-brown with banding, Luster: Dull to vitreous, Crystal structure: Microcrystalline (Trigonal), Cleavage: None (conchoidal fracture), Specific Gravity: 2.58-2.91
Formation & geological history
Formed through the deposition of silica-rich fluids in cavities or as sedimentary layers, often associated with volcanic ash or hydrothermal activity. Its red color is derived from high iron content (Hematite).
Uses & applications
Widely used in jewelry (cabochons, beads), decorative carvings, lapidary arts, and as a component in aggregate for construction and landscaping.
Geological facts
Red Jasper has been used since antiquity; it was known as the 'rain bringer' in some Native American cultures and was used in ancient Egypt for amulets and scarabs. It is a dense, opaque variety of chalcedony.
Field identification & locations
Identify by its opaque red color, smoothness when polished, and inability to be scratched by a steel knife. Common in the USA (Southwest), Brazil, India, and Australia. Collectors should look for unique banding or patterns.
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