Jasper

Physical Properties

Hardness: 6.5-7.0 (Mohs); Color: Reddish-brown, orange, earthy tones; Luster: Vitreous to waxy; Crystal structure: Hexagonal (Microcrystalline); Cleavage: None (Conchoidal fracture); Specific gravity: 2.58-2.91

Formation & Geological History

Formed through the accumulation of fine microcrystalline quartz and silica from volcanic ash or sedimentary deposits. Often occurs in hydrothermal veins or as a secondary mineral in nodules within sedimentary rocks and iron formations.

Uses & Applications

Commonly used as a gemstone for jewelry (cabochons), interior decoration, ornamental carvings, and historical utility for flint-knapping into tools.

Geological Facts

Jasper was a favorite gem in the ancient world, mentioned in biblical texts and used by early civilizations for seals and talismans. Its name is derived from the Greek word 'iaspis', meaning spotted stone.

Field Identification & Locations

Identify by its hardness (scratches glass), opaque appearance compared to agate, and its characteristic smooth, waxy fracture surface. It can be found in gravel beds, mountain ranges, and arid desert regions worldwide.

Identified on: 4/19/2026

Mode: Standard