Marble

Physical Properties

Hardness: 3-4 (Mohs scale); Color: White, gray, or mottled (as shown); Luster: Dull to pearly; Crystal structure: Trigonal; Cleavage: Perfect rhombohedral in individual crystals; Specific gravity: 2.7

Formation & Geological History

Formed through the regional or contact metamorphism of sedimentary carbonate rocks, specifically limestone or dolostone. High heat and pressure cause recrystallization of the original carbonate mineral grains.

Uses & Applications

Used widely in construction as building stone, floor tiles, and gravel. Pure white marble is prized for sculpture. In crushed form, it serves as an agricultural supplement or acidic neutralizer.

Geological Facts

The word 'marble' derives from the Greek 'marmaros,' meaning 'shining stone.' It will react and effervesce (fizz) when exposed to weak acids like vinegar or hydrochloric acid.

Field Identification & Locations

Identify in the field by its sugary, crystalline texture and its softness—it can be scratched by a steel knife. It is commonly found in mountainous regions near convergent plate boundaries.

Identified on: 4/14/2026

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