sedimentary

Jasper

Silicon dioxide (SiO2) with impurities

Hardness: 6.5-7 (Mohs scale), Color: Yellow-brown with dark banding, Luster: Vitreous to waxy, Crystal structure: Hexagonal (cryptocrystalline), Cleavage: None, Specific gravity: 2.58-2.91

Hardness: 6

Identified June 2, 2026More sedimentary →

Identify your own rocks.

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

App Store Google Play

Physical properties

Hardness: 6.5-7 (Mohs scale), Color: Yellow-brown with dark banding, Luster: Vitreous to waxy, Crystal structure: Hexagonal (cryptocrystalline), Cleavage: None, Specific gravity: 2.58-2.91

Formation & geological history

Formed through the deposition of silica from water-rich environments, often as hydrothermal veins or within sedimentary beds, where impurities like iron oxides create distinct colors.

Uses & applications

Used primarily in lapidary work, jewelry (cabochons), as an ornamental stone, and for decorative carvings.

Geological facts

Jasper is an opaque variety of chalcedony. The name comes from the Greek word 'iaspis', meaning 'spotted stone.' It has been used since antiquity for seals and amulets.

Field identification & locations

Identify in the field by its opacity (even at thin edges), smooth conchoidal fracture, and inability to be scratched by a steel knife. Frequently found as water-worn pebbles in riverbeds and on beaches.