metamorphic

Quartz-veined dark metamorphic rock, likely marble or serpentinite

Calcite- or magnesite-veined serpentinite/marble; exact identification requires testing

AI-generated identification · may be incorrect

Dark greenish-black, massive, with a contrasting white vein and minor brassy/golden patches. Likely hardness 3–6 depending on minerals; white vein may be calcite (Mohs 3) or quartz (Mohs 7), with waxy to vitreous luster and no obvious cleavage.

Identified September 6, 2026More metamorphic →

Explore Quartz-veined dark metamorphic rock, likely marble or serpentinite in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

At a glance

Common name: Quartz-veined dark metamorphic rock, likely marble or serpentinite
Scientific name: Calcite- or magnesite-veined serpentinite/marble; exact identification requires testing
Category: metamorphic
Identified: September 6, 2026
Method: Standard

AI Estimated Value

Approximately $5–$30 as a common hand specimen; $30–$100+ if attractively polished, unusually patterned, or confirmed as a collectible mineral specimen.

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

Formed through metamorphism and fluid-filled fracturing, followed by deposition of calcite, magnesite, or quartz veins; commonly associated with altered ultramafic rocks or carbonate formations. Age cannot be determined from the photograph.

Uses & applications

Used mainly as a decorative or lapidary specimen; similar serpentinite and veined marble are used for carvings, countertops, tiles, and ornamental stone.

Geological facts

The white vein is diagnostically important: it fizzes with dilute hydrochloric acid if calcite, while quartz does not. A streak, hardness test, magnet test, and close inspection of the golden grains would refine the identification.

Field identification & locations

Common in ophiolites, fault zones, and metamorphic belts worldwide, including California, Italy, Greece, New Zealand, and the Appalachians. Test inconspicuous areas because scratch and acid tests can damage the specimen.