Jasper

Physical Properties

Hardness: 6.5-7 on Mohs scale; Color: Reddish-brown, yellow, and cream mottled; Luster: Dull to waxy; Crystal Structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Formation & Geological History

Formed through the deposition of silica from water into volcanic ash or fine sediments. Its red and brown hues are typically caused by iron inclusions. It can form in various geological ages, often in marine or volcanic environments.

Uses & Applications

Used primarily as a gemstone for jewelry, in lapidary arts for carvings and cabochons, and as a decorative stone in interiors. Historically used for tool making due to its hardness and fracture pattern.

Geological Facts

Ancient civilizations called jasper the 'supreme nurturer.' It was often used in the seals of kings and as protective amulets. Red jasper is one of the most common varieties and is colored by iron oxide (hematite).

Field Identification & Locations

Identify in the field by its hardness (it cannot be scratched by a steel knife), opaque transparency, and smooth, waxy fracture surfaces. Commonly found in riverbeds, deserts, and volcanic regions worldwide.

Identified on: 4/14/2026

Mode: Standard