sedimentary
Red Jasper
Silicon Dioxide (SiO2) with iron oxide 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 process of silicification, where silica-rich fluids permeate porous sedimentary or volcanic rocks. The red color comes from high concentrations of iron oxide (hematite) during formation.
Uses & applications
Commonly used in jewelry (cabochons, beads), decorative carvings, lapidary arts, and as a landscaping stone.
Geological facts
Red Jasper has been used since antiquity; it was known as the 'stone of endurance' and was used in the breastplate of the High Priest in Biblical times. It is a variety of chalcedony.
Field identification & locations
Identify by its deep red color, high hardness (will scratch glass), and smooth, waxy to dull surface. It is commonly found globally, particularly in environments like Brazil, India, and the southwestern USA.
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