sedimentary
Red Jasper
Red Jasper (SiO2) with Hematite inclusions
Hardness: 6.5-7 (Mohs scale), Color: Brick red to brownish-red, Luster: Vitreous to dull, Crystal Structure: Trigonal (microcrystalline), 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: Brick red to brownish-red, Luster: Vitreous to dull, Crystal Structure: Trigonal (microcrystalline), Cleavage: None (conchoidal fracture), Specific Gravity: 2.58-2.91
Formation & geological history
Formed through the deposition of silica from hydrothermal solutions or volcanic ash, often associated with sedimentary iron formations. Its red color comes from iron oxide (hematite) inclusions.
Uses & applications
Used extensively in jewelry as cabochons or beads, for lapidary art, aquarium decor, and as a popular specimen for crystal collecting and tumbling.
Geological facts
Known as the 'Stone of Endurance' in ancient times, red jasper was used by Egyptians for amulets and by Native Americans as a protection stone. It is an opaque variety of chalcedony.
Field identification & locations
Identify by its deep red color, high hardness (will scratch glass), and lack of transparency. Common in riverbeds and gravel deposits in regions like the Western United States, South Africa, and Brazil.
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