Red Jasper (Opaque Chalcedony)

Physical Properties

Hardness: 6.5-7 (Mohs scale); Color: Brick red to brownish-red with grey mottling; Luster: Vitreous to waxy (smooth when wet/polished); Crystal Structure: Microcrystalline; Cleavage: None/Conchoidal fracture; Specific gravity: 2.58-2.91.

Formation & Geological History

Formed through the deposition of silica from water-bearing solutions, often in sedimentary environments or as primary minerals in hydrothermal veins. The red color is caused by iron (III) inclusions that were present during the solidification process, spanning many geological eras.

Uses & Applications

Used primarily as a gemstone for jewelry (cabochons, beads), decorative ornaments, and metaphysical collecting. Historically used for seals and talismans.

Geological Facts

Ancient Egyptians associated red jasper with the blood of Isis and used it in amulets. It is an opaque variety of chalcedony that never loses its color, even when weathered heavily by the ocean.

Field Identification & Locations

Identify in the field by its opacity (unlike translucent carnelian), its high hardness (won't scratch with a knife), and its smooth, water-worn texture on beaches. Found globally, especially on coastal shorelines and riverbeds.

Identified on: 4/26/2026

Mode: Standard