Jasper
Silicon dioxide (SiO2)
Rock Type: sedimentary

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