Marble

Physical Properties

Hardness: 3 on Mohs scale; Color: typically white but can be grayish; Luster: vitreous to pearly; Crystal structure: Trigonal (granular/massive); Cleavage: Perfect rhombohedral (in calcite crystals); Specific Gravity: 2.7

Formation & Geological History

Formed when limestone is subjected to the heat and pressure of metamorphism. It is composed primarily of the mineral calcite. The age varies based on local geology, ranging from Precambrian to Cenozoic.

Uses & Applications

Widely used in construction, sculpture, flooring, and as an industrial acid neutralizer. High-purity white marble is often used as a filler in paper, paint, and plastics.

Geological Facts

Marble has been the preferred medium for Greek and Roman sculptors due to its relative softness and isotropic properties. The word 'marble' derives from the Greek 'marmaros', meaning 'shining stone'.

Field Identification & Locations

Can be identified in the field by its granular, crystalline appearance and its reaction to dilute hydrochloric acid (it will fizz). Found in mountainous regions like the Apuan Alps in Italy or the Appalachian Mountains.

Identified on: 4/29/2026

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