White Marble

Recrystallized Calcite (CaCO3)

Rock Type: metamorphic

White Marble

Physical Properties

Hardness: 3 on Mohs scale; Color: Pure white to off-white; Luster: Vitreous to pearly; Crystal structure: Trigonal/Hexagonal (recrystallized grains); Cleavage: Perfect rhombohedral (in individual crystals); 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 a interlocking mosaic of calcite.

Uses & Applications

Widely used in construction for tiles and countertops, sculpture, architecture, and as an industrial filler in paints and paper.

Geological Facts

Pure white marble, like this specimen, indicates that the parent limestone was very pure and lacked minerals like clay, silt, or sand that create the 'veining' seen in many marbles.

Field Identification & Locations

Can be identified in the field by its characteristic softness (can be scratched with a copper penny or steel) and its vigorous reaction (effervescence) when exposed to a drop of cold dilute hydrochloric acid.

Identified on: 4/20/2026

Mode: Standard