sedimentary

Jasper (Red Jasper)

Silicon Dioxide (SiO₂)

Hardness: 6.5-7 Mohs scale; Color: Red, brown, earthy tones; Luster: Dull to vitreous; Crystal Structure: Microcrystalline/cryptocrystalline (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58–2.91.

Hardness: 6
Color: Red, brown, earthy tones
Luster: Dull to vitreous

Identified March 29, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from the deposition of silica from volcanic ash or water circulation through sedimentary rocks. The red color is caused by the inclusion of iron oxide (hematite). It can be found in rocks of various ages ranging from Precambrian to recent times.

Uses & applications

Commonly used in lapidary arts for jewelry, ornaments, seal stones, and as a decorative stone in mosaics and furniture. Historically used to create sharp tools and arrowheads.

Geological facts

Jasper was a favorite gem in the ancient world; its name can be traced back in Hebrew, Assyrian, Greek, and Latin. It is considered one of the traditional birthstones for March.

Field identification & locations

Identify by its opaque nature (unlike agate which is translucent), its smooth conchoidal fracture, and its inability to be scratched by a steel knife. Frequently found in riverbeds, deserts, and volcanic regions globally.