sedimentary

Red Jasper (Banded Jasper)

Silicon Dioxide (SiO2) with Hematite impurities

Hardness: 6.5-7 (Mohs scale), Color: Brick red with dark grey or black banding, Luster: Vitreous to dull, Crystal Structure: Microcrystalline (Trigonal), Cleavage: None (Conchoidal fracture), Specific Gravity: 2.58-2.91

Hardness: 6

Identified March 21, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the deposition of silica from volcanic ash or hydrothermal fluids in sedimentary environments. Its red color comes from iron oxide (hematite) inclusions. Most jasper dates back to various geological periods, commonly found in deposits millions of years old.

Uses & applications

Commonly used in lapidary work for cabochons, beads, and ornaments. In industry, it is sometimes used as a flux in steel production (if found in large iron-bearing formations) or as a decorative stone in landscaping and architecture.

Geological facts

Jasper has been used by humans for thousands of years; it was a favorite in the ancient world for making cylinder seals and amulets. The 'banded' variety seen here often signifies alternating cycles of silica and iron deposition.

Field identification & locations

Identify in the field by its high hardness (won't be scratched by a steel knife), opaque 'earthy' appearance, and characteristic waxy luster when polished. Commonly found in areas with high volcanic or metamorphic activity like the Western US, Brazil, and India.

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