Jasper

Physical Properties

Hardness: 6.5-7 (Mohs); Color: tan, yellow, orange-ish; Luster: vitreous to waxy; Structure: cryptocrystalline quartz; Cleavage: none (conchoidal fracture).

Formation & Geological History

Formed from silica-rich fluids circulating through volcanic ash or sedimentary layers. This process of petrification or chemical precipitation occurs over millions of years, typically during the Cretaceous to Tertiary periods.

Uses & Applications

Commonly used as a gemstone, for lapidary work (cabs and beads), decorative ornaments, and healing crystals in various cultures.

Geological Facts

Jasper is an opaque variety of chalcedony. It takes such a high polish that it has been used historically for making seals and vases in ancient Mediterranean civilizations.

Field Identification & Locations

Identify by its high hardness (won't be scratched by a steel knife) and its smooth, waxy feel. Often found in riverbeds, coastal gravels, or desert regions worldwide, particularly in the western USA (Oregon, Idaho).

Identified on: 4/13/2026

Mode: Standard