Jasper

Physical Properties

Hardness: 6.5-7 (Mohs); Color: Red, brown, and gray; Luster: Dull to vitreous; Crystal Structure: Microcrystalline/Cryptocrystalline (Hexagonal/Trigonal); Cleavage: None; Specific Gravity: 2.58-2.91

Formation & Geological History

Formed through the infiltration of silica-rich fluids into volcanic ash or fine-grained sediments. Red coloration is typically caused by iron (hematite) inclusions. Can range from Precambrian to recent geological ages.

Uses & Applications

Commonly used in lapidary work for making cabochons, beads, and decorative ornaments. Also sought after by rockhounds and mineral collectors for its unique patterns.

Geological Facts

Jasper is a variety of chalcedony. Historically, it was known as the 'supreme nurturer' in ancient cultures and has been used for seals and amulets for thousands of years.

Field Identification & Locations

Identify in the field by its waxy to dull luster, lack of cleavage, and smooth conchoidal fracture. Often found as rounded pebbles in stream beds or glacial till. Commonly found in the Western United States, India, and Brazil.

Identified on: 4/22/2026

Mode: Standard