sedimentary

Red Jasper

Cryptocrystalline Quartz (SiO2 with Iron oxide inclusions)

AI-generated identification · may be incorrect

Hardness: 6.5-7 on Mohs scale; Color: Red to brownish-red; Luster: Dull to vitreous; Crystal Structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Hardness: 6
Color: Red to brownish-red
Luster: Dull to vitreous

Identified June 17, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Red to brownish-red; Luster: Dull to vitreous; Crystal Structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Formation & geological history

Formed when silica-rich fluids permeate sedimentary rocks or volcanic ash, with the red color provided by high concentrations of iron oxide (hematite). It often forms in hydrothermal veins or as nodules in volcanic rocks.

Uses & applications

Commonly used as a gemstone for jewelry (cabochons, beads), decorative carvings, and as a popular specimen for gemstone tumbling and crystal collecting.

Geological facts

Red Jasper has been used since antiquity in seals and ornaments, and ancient Egyptians associated it with the blood of Isis. It is a variety of chalcedony that is essentially opaque due to its high mineral inclusion content.

Field identification & locations

Identify in the field by its deep red color, extreme hardness (cannot be scratched by a steel knife), and characteristic smooth, shell-like conchoidal fracture. Found worldwide in areas like the USA (Southwest), India, and Brazil.