Jasper (Banded Jasper)

Physical Properties

Hardness: 6.5–7 (Mohs scale); Color: Brown, tan, cream, and grey bands; Luster: Vitreous to waxy; Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.58–2.91

Formation & Geological History

Formed through the deposition of silica from mineral-rich waters in sedimentary environments, often associated with volcanic ash or iron-rich deposits. This specimen likely dates from the Precambrian to Cenozoic eras.

Uses & Applications

Used primarily in lapidary work, jewelry (cabochons and beads), ornamental carvings, and as a popular collector's item due to its unique banding patterns.

Geological Facts

Jasper is an opaque variety of chalcedony. The banding in 'picture jasper' or 'banded jasper' is often caused by flows of mineralized water or wind-deposited layers of ash that were later petrified by silica.

Field Identification & Locations

Identify by its hardness (it can scratch glass) and its opaque, smooth surface when tumbled. It is commonly found in riverbeds, deserts, and volcanic regions globally, notably in the Western USA, Brazil, and India.

Identified on: 4/26/2026

Mode: Standard