Jasper

Physical Properties

Hardness: 6.5-7.0 (Mohs scale); Color: Red, brown, and tan mottled pattern (due to iron inclusions); Luster: Waxy to dull; Crystal structure: Hexagonal (Microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Formation & Geological History

Formed during the process of sedimentation and silica-rich hydrothermal activity. Often found in nodules, veins, or as replacements in sedimentary rocks and as impurities within volcanic deposits.

Uses & Applications

Commonly used as a gemstone for jewelry (cabochons, beads), lapidary art, ornaments, and historically as a material for knapped tools like arrowheads.

Geological Facts

Jasper was a favorite gem in the ancient world; its name can be traced back in Arabic, Persian, Greek, and Latin. It is also mentioned frequently in the Bible and is the birthstone for March in some traditions.

Field Identification & Locations

Identify by its opaque nature (unlike agate), smooth waxy feel, and characteristic conchoidal fracture (curved breakages). Look for it in riverbeds or coastal areas where silica-rich stones aggregate.

Identified on: 4/19/2026

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