sedimentary
Red Jasper
Silicon Dioxide with Iron Oxide (SiO2)
Hardness: 6.5-7 on Mohs scale; Color: Terracotta-red to brownish-red; Luster: Vitreous to waxy; Crystal Structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.58–2.91
- Hardness
- 6
- Color
- Terracotta-red to brownish-red
- Luster
- Vitreous to waxy
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Physical properties
Hardness: 6.5-7 on Mohs scale; Color: Terracotta-red to brownish-red; Luster: Vitreous to waxy; Crystal Structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.58–2.91
Formation & geological history
Formed when silica-rich fluids permeate through volcanic or sedimentary rock, often in hydrothermal veins or as nodules. Its red color comes from high concentrations of iron inclusions. It can form in various geological ages and is often found in prehistoric sedimentary deposits.
Uses & applications
Used primarily in jewelry as cabochons, beads, and tumbled stones. It is also used in decorative mosaics, ornaments, and remains a very popular stone for mineral collectors and practitioners of lithotherapy.
Geological facts
In antiquity, Red Jasper was known as the 'bringer of rain' and was widely used in ancient Egypt for amulets and scarabs. It is an opaque variety of chalcedony that owes its opacity to its high mineral inclusion content.
Field identification & locations
Identify by its deep red color, opacity (light will not pass through it even on thin edges), and its ability to scratch glass. It is commonly found in India, Brazil, South Africa, and the southwestern United States.
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