Riverstone Jasper (Chert variant)

Physical Properties

Hardness: 6.5-7 on Mohs scale. Color: Olive green with tan and gray mottling. Luster: Waxy to dull. Crystal Structure: Microcrystalline/cryptocrystalline (trigonal). Cleavage: None (conchoidal fracture). Specific Gravity: 2.6-2.9.

Formation & Geological History

Formed from the deposition of microcrystalline silica over millions of years. This specific specimen is a tumbled river stone, shaped and smoothed by hydraulic action in a high-energy water environment such as a riverbed or shoreline.

Uses & Applications

Used primarily for decorative purposes, landscape architecture, worry stones/meditation, and occasionally in lapidary work for inexpensive jewelry or tumbled stone collections.

Geological Facts

Jasper is an opaque variety of chalcedony. The green color in specimens like this is often caused by silicate mineral inclusions like chlorite or iron oxides. It has been used since antiquity for making tools and seals.

Field Identification & Locations

Identify in the field by its smoothness, opacity, and ability to scratch glass. Commonly found in riverbeds, glacial deposits, and sedimentary basins worldwide. It is a common 'find' for beachcombers and hikers.

Identified on: 5/17/2026

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