metamorphic

Likely polished greenstone or serpentine inlay

Serpentine-group mineral, commonly antigorite/lizardite; possibly nephrite jade

AI-generated identification · may be incorrect

The small square appears dark green, gray, and mottled with a polished or glossy surface. Serpentine has Mohs hardness 2.5–5.5, waxy to vitreous luster, poor cleavage, and variable specific gravity around 2.5–2.6; nephrite is tougher and harder, about 6–6.5.

Identified September 5, 2026More metamorphic →

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Physical properties

Formation & geological history

Serpentine forms when ultramafic mantle rocks are hydrated during metamorphism, commonly in tectonic belts; nephrite forms through metamorphic alteration of magnesium-rich rocks. A precise age and identification cannot be determined from this image.

Uses & applications

Likely decorative furniture inlay or a small ornamental insert; similar material is used for carvings, cabochons, beads, and architectural decoration. Common serpentine pieces generally have modest value.

Geological facts

The specimen is set into wood, so it is clearly human-processed geological material. The image is too small to distinguish serpentine from nephrite, chlorite-rich stone, or another green metamorphic rock.

Field identification & locations

Look for green mottling, a smooth waxy polish, relatively low hardness, and absence of obvious crystal faces; a hardness, density, and refractive-index test would help. Serpentine is common in California, Italy, New Zealand, Canada, and the Ural Mountains; nephrite occurs in Canada, China, New Zealand, and Siberia.