metamorphic

Coarse-grained marble or calcite-rich metamorphic rock

Calcite (CaCO₃), likely marble with mica and silicate minerals

AI-generated identification · may be incorrect

Gray-white, coarse crystalline texture with a glassy to pearly luster; calcite has Mohs hardness 3, rhombohedral cleavage, and fizzes strongly in dilute hydrochloric acid. The dark grains may be mica, amphibole, or other silicates; crystal form is granular and interlocking.

Identified September 7, 2026More metamorphic →

Explore Coarse-grained marble or calcite-rich metamorphic rock 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: Coarse-grained marble or calcite-rich metamorphic rock
Scientific name: Calcite (CaCO₃), likely marble with mica and silicate minerals
Category: metamorphic
Identified: September 7, 2026
Method: Standard

AI Estimated Value

Typically $2–$15 as an unattributed hand specimen; approximately $20–$75 if provenance, mineral associations, or appearance are distinctive.

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

Likely recrystallized limestone or dolostone during regional or contact metamorphism, generally formed in the Precambrian to Phanerozoic. Exact age and identity require acid testing, thin-section study, or mineral analysis.

Uses & applications

Used as decorative stone, aggregate, and occasionally in sculpture or classrooms; attractive pieces may be collected but are usually low-value.

Geological facts

Calcite marble can resemble quartz-rich rocks, but calcite is softer and reacts with acid. A steel nail or knife may scratch exposed calcite, while quartz will not.

Field identification & locations

Common in metamorphic belts worldwide, including Italy, Greece, Vermont, Colorado, and India. Test a fresh surface with dilute acid, inspect cleavage, and check whether the pale crystals scratch with steel.