sedimentary

Jasper

Jasper (Silicon Dioxide, SiO2)

Hardness: 6.5-7 (Mohs scale). Color: Red-orange to yellowish brown with mottled patterns. Luster: Dull to vitreous/waxy. Crystal Structure: Hexagonal/Cryptocrystalline. Cleavage: None (conchoidal fracture). Specific Gravity: 2.58-2.91.

Hardness: 6
Color: Red-orange to yellowish brown with mottled patterns
Luster: Dull to vitreous/waxy

Identified June 15, 2026More sedimentary →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed through the deposition of silica from water into volcanic ash or fine-grained sediments. Over time, the silica crystallizes into microcrystalline quartz. Commonly found in Mesozoic to Cenozoic formations.

Uses & applications

Widely used as a gemstone for jewelry (cabochons), oratory items, seals, and as decorative stone in lapidary arts. Historically used for tool making due to its fracture pattern.

Geological facts

Jasper is an opaque variety of chalcedony. Its vibrant red and orange colors are typically caused by iron inclusions (hematite). Ancient civilizations often believed it possessed protective or healing powers.

Field identification & locations

Identify by its opacity (even on thin edges), conchoidal fracture, and inability to be scratched by a steel knife. Commonly found in riverbeds, desert pavements, and near volcanic regions. Look for waxy surface texture.