Marble

Physical Properties

Hardness: 3 on Mohs scale; Color: Grayish-white; Luster: Pearly to sub-vitreous; Crystal Structure: Trigonal/Rhombohedral crystals; Cleavage: Perfect rhombohedral (in calcite grains); Specific Gravity: 2.7

Formation & Geological History

Formed when sedimentary carbonate rocks (limestone or dolostone) are subjected to high heat and pressure, causing recrystallization into a dense interlocking mosaic of calcite or dolomite crystals.

Uses & Applications

Commonly used in construction, sculpture, flooring, and as an industrial source of calcium carbonate for paper and paint production.

Geological Facts

Marble has been used since antiquity for famous sculptures like Michelangelo's David and the Parthenon. Pure white marble is the result of metamorphism of very pure limestone.

Field Identification & Locations

Identify in the field by its softness (can be scratched by a copper penny or steel) and its vigorous reaction to dilute hydrochloric acid. It often feels 'sugary' or granular to the touch.

Identified on: 4/25/2026

Mode: Standard