Banded calcite marble

Typically Mohs hardness 3, white to gray with tan and pale green-gray banding, vitreous to pearly luster, and interlocking calcite crystals; calcite shows rhombohedral cleavage and effervesces strongly in dilute hydrochloric acid. The specimen appears coarse-grained and foliated/banded, though exact minerals require testing.

Formed when limestone or dolostone recrystallized during regional or contact metamorphism, commonly during Paleozoic–Mesozoic mountain-building; its precise age and locality cannot be determined from the image.

Used as decorative and architectural stone, sculptures, countertops, aggregate, and a source of calcium carbonate; attractive pieces may be polished for lapidary display.

The pale bands may represent calcite-rich layers, while gray-green zones can contain mica, tremolite, or other silicates. Marble is chemically reactive with acids, unlike quartz-rich rocks.

Look for a sugary crystalline texture, relatively soft surface, and vigorous acid fizz; a steel knife may scratch it, while quartz will not. Common worldwide in metamorphic belts, including Italy, Greece, Vermont, Colorado, and India.