Jasper

Physical Properties

Hardness: 6.5-7 (Mohs scale); Color: Variegated greens, grays, and creams; Luster: Vitreous to waxy; Crystal structure: Trigonal (Microcrystalline); Cleavage: None; Specific gravity: 2.58-2.91

Formation & Geological History

Jasper is an opaque variety of chalcedony formed through the deposition of silica from water. This specimen likely formed in hydrothermal veins or as a replacement in sedimentary beds, often influenced by the presence of iron or clay impurities that create its unique banding.

Uses & Applications

Commonly used for lapidary work, cabochons, jewelry, ornamental carvings, and as a popular stone for tumbling and collecting.

Geological Facts

Jasper has been used since antiquity; it was known in ancient Mesopotamian and Greek cultures as a protective stone. The term comes from the Greek word 'iaspis', meaning 'spotted stone'.

Field Identification & Locations

Identify in the field by its hardness (will scratch glass), smooth conchoidal fracture, and complete opacity (light will not pass through it). It is frequently found in riverbeds or coastal regions.

Identified on: 4/13/2026

Mode: Standard