sedimentary

Red Jasper

Silicon Dioxide (SiO₂)

Hardness: 6.5–7 (Mohs scale); Color: Brick red to brownish-red; Luster: Vitreous to waxy; Crystal Structure: Hexagonal (trigonal) microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.58–2.91

Hardness: 6
Color: Brick red to brownish-red
Luster: Vitreous to waxy

Identified March 28, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed via the deposition of silica from hydrothermal solutions or volcanic ash into sedimentary basins, often containing high levels of iron inclusions (hematite) which provide the red pigment. It can be found in formations ranging from Precambrian to recent ages.

Uses & applications

Used primarily in lapidary work for cabochons, beads, and polished spheres (like the one pictured). It is also used in decorative masonry, mosaics, and as a popular stone for metaphysical or geological collecting.

Geological facts

Jasper has been one of the most significant gemstones of antiquity, mentioned in the Bible as one of the twelve stones in the High Priest's Breastplate. The red color is specifically caused by dispersed iron oxide inside the quartz matrix.

Field identification & locations

Identify in the field by its opaque nature (unlike agate which is translucent), its smooth conchoidal fracture when broken, and its inability to be scratched by a steel knife. Common locations include Brazil, India, USA (Southwest), and Madagascar.