Sedimentary (if natural Jasper) or Artificial (if Slag)

Jasper (Multi-colored) / Sea Glass Slag

Silicon Dioxide (SiO2) with impurities of Iron Oxide

AI-generated identification · may be incorrect

Hardness of 6.5-7 on the Mohs scale. Opaque with a waxy to vitreous luster. This specific piece shows a conchoidal fracture and deep red and green coloration. Small white calcified circles are barnacle attachments.

Identified March 12, 2026More sedimentary (if natural jasper) or artificial (if slag) →

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Physical properties

Formation & geological history

Formed through the accumulation of silica in volcanic ash or sedimentary deposits (naturally) or as a byproduct of glass manufacturing (artificially). This specimen has been submerged in a marine environment, evidenced by the barnacles and water-worn edges.

Uses & applications

Used primarily in lapidary work, jewelry making (cabochons), and as aquarium or decorative stones.

Geological facts

The presence of barnacles indicates this specimen spent significant time in intertidal zones or underwater. Jasper has been used since antiquity for seals and talismans, while 'sea glass slag' is highly sought after by beachcombers for its unique swirled patterns.

Field identification & locations

Identify by its extreme hardness (cannot be scratched by a steel knife) and smooth, shell-like fracture surface. Commonly found on coastlines near ancient volcanic or industrial areas. Collectors should look for unique 'brecciated' or multi-colored patterns.