Jasper

Silicon dioxide (SiO2)

Rock Type: sedimentary

Jasper

Physical Properties

Hardness: 6.5-7 (Mohs scale); Color: Yellowish-brown to reddish-brown; Luster: Dull to waxy; Crystal structure: Microcrystalline/Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91

Formation & Geological History

Usually formed from the deposition of silica from water-rich environments like hot springs or through the replacement of organic or volcanic materials. This specimen appears as a river-tumbled or water-worn nodule.

Uses & Applications

Used primarily in lapidary arts for cabochons, beads, and carvings, as well as an ornamental stone and a collector specimen.

Geological Facts

Jasper is an opaque variety of chalcedony. The presence of iron oxides like goethite or hematite gives it the earthen yellow and red tones seen here.

Field Identification & Locations

Identify in the field by its hardness (cannot be scratched by a steel blade), dull luster on unpolished surfaces, and smooth, rounded water-worn texture. Common in riverbeds and gravel deposits worldwide.

Identified on: 4/23/2026

Mode: Standard