sedimentary
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Hardness: 6.5-7 on Mohs scale. Color: Opaque brick red to brownish-red. Luster: Vitreous to waxy. Crystal Structure: Hexagonal/Trigonal (Microcrystalline). Cleavage: None (conchoidal fracture). Specific Gravity: 2.58-2.91.
- Hardness
- 6
- Color
- Opaque brick red to brownish-red
- Luster
- Vitreous to waxy
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Physical properties
Hardness: 6.5-7 on Mohs scale. Color: Opaque brick red to brownish-red. Luster: Vitreous to waxy. Crystal Structure: Hexagonal/Trigonal (Microcrystalline). Cleavage: None (conchoidal fracture). Specific Gravity: 2.58-2.91.
Formation & geological history
Formed primarily through the deposition of silica-rich fluids in volcanic or sedimentary environments. The red color comes from high concentrations of iron oxide (hematite) that were trapped as the silica solidified into cryptocrystalline quartz. It is often found in prehistoric sedimentary deposits.
Uses & applications
Used extensively in jewelry for cabochons and beads, ornamental carvings, seals, and as a decorative stone in mosaics and garden landscaping. It is also a popular specimen for rock tumbling.
Geological facts
Red Jasper was historically known as the 'Stone of Endurance' and was used by ancient civilizations for protective amulets. It is an opaque variety of chalcedony. Some civilizations believed it could stop bleeding and increase fertility.
Field identification & locations
Identify in the field by its deep red color, opacity (light will not pass through edges), and its smooth, glass-like fracture. It is commonly found in riverbeds, desert landscapes, and regions with ancient volcanic activity like the Western United States, South Africa, and Brazil.
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