Jasper

Silicon dioxide (SiO2)

Rock Type: sedimentary

Jasper

Physical Properties

Hardness: 6.5-7 (Mohs scale); Color: Pale sage green with tan banding; Luster: Vitreous to waxy; Crystal structure: Trigonal (cryptocrystalline); Specific gravity: 2.6-2.9.

Formation & Geological History

Formed through the infiltration of silica-rich fluids into volcanic ash or sedimentary deposits, typically in hydrothermal or shallow sea environments. This specimen is a water-worn river pebble.

Uses & Applications

Used primarily in lapidary work for making cabochons, beads, and decorative ornaments. Also used as a healing stone in metaphysical practices and as decorative landscaping gravel.

Geological Facts

Jasper is an opaque variety of chalcedony. The name comes from the Old French word 'jaspre', which means spotted or speckled stone, though this specific piece shows more banding than spotting.

Field Identification & Locations

Identify in the field by its high hardness (it cannot be scratched by a steel pocket knife) and smooth, non-porous surface. Often found in riverbeds and on beaches worldwide where volcanic activity once occurred.

Identified on: 5/20/2026

Mode: Standard