metamorphic

Likely weathered marble or calcite-rich metamorphic rock

Calcite (CaCO₃), probably marble; exact identification requires testing

AI-generated identification · may be incorrect

Gray-white, massive and granular with dull to weakly glassy luster; apparent coarse calcite texture and rusty-brown weathering. Calcite has Mohs hardness 3, rhombohedral cleavage, and specific gravity about 2.71; it should fizz vigorously with dilute hydrochloric acid or strong vinegar if fresh surfaces are exposed.

Identified September 8, 2026More metamorphic →

Explore Likely weathered 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

Physical properties

Formation & geological history

Likely recrystallized limestone (marble) formed during metamorphism, commonly Paleozoic or older, though age cannot be determined visually. The brown coating reflects oxidation and surface weathering.

Uses & applications

Marble and calcite are used for aggregate, lime, cement, dimension stone, and decorative material; this rough specimen has mainly educational or collecting value.

Geological facts

The photograph cannot reliably distinguish marble from calcite-rich vein rock, limestone, or dolostone. A steel nail should not scratch calcite, while a knife may leave a mark.

Field identification & locations

Look for interlocking white calcite grains, rhombohedral cleavage, and acid effervescence; dolomite reacts weakly unless powdered. Common sources include metamorphic belts and carbonate-hosted veins worldwide.