Marble

Physical Properties

Hardness: 3 on Mohs scale; Color: White with grey or black veining; Luster: Sub-vitreous to waxy; Structure: Granoblastic, medium to coarse-grained crystals; Cleavage: Perfect rhombohedral in individual calcite grains; Specific Gravity: 2.7

Formation & Geological History

Formed through the regional or contact metamorphism of sedimentary limestone or dolostone. High heat and pressure cause the original carbonate mineral grains to recrystallize into an interlocking mosaic.

Uses & Applications

Used extensively in construction for floor tiles and countertops, sculpture throughout history, and as a source of calcium carbonate in industrial fillers and pharmaceuticals.

Geological Facts

Pure white marble is the result of metamorphism of a very pure limestone. The characteristic swirls and veins of many colored marble varieties are usually due to various mineral impurities such as clay, silt, sand, or iron oxides.

Field Identification & Locations

Identify in the field by its softness (it can be scratched by a copper penny or steel knife) and its effervescence when exposed to dilute hydrochloric acid. Commonly found in mountainous regions underlain by limestone.

Identified on: 4/27/2026

Mode: Standard