Jasper

Physical Properties

Hardness: 6.5-7 (Mohs scale), Color: Red, brown, and yellow hues, Luster: Vitreous to dull, Structure: Microcrystalline quartz, Cleavage: None/Conchoidal fracture, Specific Gravity: 2.58-2.91

Formation & Geological History

Formed from silica-rich fluids (typically from volcanic ash or marine sediments) permeating through rock, often filling cavities or forming layers; colored by iron oxides. Geological age varies greatly from Precambrian to Cenozoic.

Uses & Applications

Used primarily in lapidary work, jewelry (cabochons), interior decoration, and as a popular collector's river/beach stone.

Geological Facts

The name 'Jasper' is derived from the Greek word 'iaspis', meaning spotted stone. It has been used since antiquity for seals and amulets, often mentioned in early literature as a protective stone.

Field Identification & Locations

Identify by its opacity (unlike translucent agate) and smooth, waxy surface when wet. Commonly found on coastlines, in gravel pits, and riverbeds where volcanic rocks have eroded.

Identified on: 5/3/2026

Mode: Standard