sedimentary

Red Jasper (Chert)

Silicon Dioxide (SiO2) with iron inclusions

AI-generated identification · may be incorrect

Hardness: 6.5-7 Mohs; Color: Brick red to brownish-red; Luster: Dull to waxy; Crystal structure: Microcrystalline/Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91

Hardness: 6
Color: Brick red to brownish-red
Luster: Dull to waxy

Identified June 25, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 Mohs; Color: Brick red to brownish-red; Luster: Dull to waxy; Crystal structure: Microcrystalline/Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91

Formation & geological history

Formed when silica-rich fluids permeate through sedimentary or volcanic rock, often in hydrothermal environments. The red color comes from iron oxide (hematite) inclusions incorporated during the formation process.

Uses & applications

Used primarily as decorative stone, in lapidary work for cabochons and beads, and as an ornamental gemstone. Historically used for making tools due to its conchoidal fracture.

Geological facts

Jasper has been used by ancient civilizations for seals and jewelry for thousands of years. It is a variety of chalcedony that is opaque due to high mineral content.

Field identification & locations

Identify by its characteristic red color, extreme hardness (it will scratch glass), and smooth, curved fracture surfaces. Commonly found in riverbeds and coastal areas worldwide.