Jasper

Silicon dioxide (SiO2)

Rock Type: sedimentary

Jasper

Physical Properties

Hardness: 6.5-7 (Mohs); Color: Tan, beige, brown with white veining; Luster: Vitreous to dull; Crystal structure: Hexagonal (Microcrystalline); Cleavage: None (Conchoidal fracture); Specific gravity: 2.58-2.91

Formation & Geological History

Formed through the accumulation of fine silica-rich sediments or volcanic ash that undergoes lithification. Most jasper forms in hydrothermal environments or through the replacement of organic debris in sedimentary beds.

Uses & Applications

Used primarily in lapidary arts for cabochons, beads, and decorative carvings. It is also a popular collector's stone due to its unique patterns.

Geological Facts

Jasper is an opaque variety of chalcedony. The name comes from the Greek word 'iaspis', meaning 'spotted stone'. It was one of the stones used in the breastplate of the High Priest in biblical times.

Field Identification & Locations

Identify in the field by its hardness (will scratch glass), smooth waxy feel when polished, and lack of transparency. Common in riverbeds, deserts, and volcanic regions globally.

Identified on: 4/15/2026

Mode: Standard