Marble

Physical Properties

Hardness: 3 on Mohs scale; Color: White to off-white; Luster: Vitreous to pearly; Crystal structure: Trigonal/Hexagonal (granular texture); Cleavage: Perfect rhombohedral; Specific gravity: 2.7

Formation & Geological History

Formed when sedimentary limestone is subjected to high heat and pressure (metamorphism), causing recrystallization of the original carbonate mineral grains. Can range from Precambrian to Cenozoic in age.

Uses & Applications

Used extensively in sculpture, high-end building construction (countertops, flooring), monuments, and as a source for calcium carbonate in agricultural or industrial applications.

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 sugary (saccharoidal) texture, softness compared to quartz, and a vigorous reaction (fizzing) when exposed to dilute hydrochloric acid. Commonly found in mountainous regions underlain by ancient carbonate rocks.

Identified on: 4/21/2026

Mode: Standard