mineral

Likely polished green serpentine or aventurine

Serpentine-group minerals, commonly antigorite/lizardite; alternatively quartz-rich green aventurine

AI-generated identification · may be incorrect

Small rounded specimen with dark olive-green color and glittery surface, likely polished or wet. Serpentine has Mohs hardness 2.5–4, waxy to greasy luster, poor cleavage, and specific gravity about 2.5–2.6; aventurine is harder, about 6.5–7, with quartz’s vitreous luster.

Identified August 15, 2026More mineral →

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At a glance

Common name: Likely polished green serpentine or aventurine
Scientific name: Serpentine-group minerals, commonly antigorite/lizardite; alternatively quartz-rich green aventurine
Category: mineral
Identified: August 15, 2026
Method: Standard

AI Estimated Value

Approximately $1–$10 for a small common tumbled piece; attractive or well-identified specimens may sell for $10–$40.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Serpentine forms when ultramafic rocks such as peridotite undergo hydrothermal alteration, commonly during mountain-building; aventurine forms in silica-rich veins or metamorphic rocks. Exact age cannot be determined from the image.

Uses & applications

Serpentine is used for carvings, ornamental stone, and historically some architectural materials; green aventurine is used for beads, cabochons, and inexpensive jewelry.

Geological facts

The glitter may come from magnetite, mica, or polished reflective mineral grains. Serpentine can resemble jade but is generally softer and less dense.

Field identification & locations

Field tests are useful: serpentine is relatively soft and may scratch with a steel knife, whereas aventurine will not; a close inspection or hardness test is needed for confident identification. Common sources include California, Italy, New Zealand, Canada, and Russia.