Jasper

Physical Properties

Hardness: 6.5-7 on Mohs scale; Color: Red, orange, yellow (due to iron oxides); Luster: Vitreous to waxy; Crystal structure: Hexagonal/Trigonal (Microcrystalline); Cleavage: None; Specific Gravity: 2.58-2.91.

Formation & Geological History

Formed through the deposition of silica in hydrothermal veins or as a secondary mineral in volcanic rocks. This specimen appears to be a stream-tumbled or polished pebble, formed by water erosion over millennia.

Uses & Applications

Commonly used in lapidary arts, jewelry (cabochons and beads), ornamental ornaments, and as a popular specimen for rock tumbling and collection.

Geological Facts

Jasper is an opaque variety of chalcedony. The name 'jasper' comes from the Greek word 'iaspis', meaning 'spotted stone'. It was highly prized in the ancient world for its vibrant colors and toughness.

Field Identification & Locations

Identify in the field by its opacity (it does not transmit light even at the edges), smooth conchoidal fracture, and high hardness. Commonly found in gravel beds, rivers, and volcanic regions worldwide.

Identified on: 4/13/2026

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