Marble

Physical Properties

Hardness: 3 on Mohs scale; Color: typically white to gray, but can be many colors; Luster: vitreous to pearly; Crystal structure: Trigonal (rhombohedral cleavage visible in small specimen); Cleavage: Perfect rhombohedral.

Formation & Geological History

Forms through the regional or contact metamorphism of limestone or dolostone under high temperature and pressure, causing recrystallization into a dense interlocking grid of carbonate minerals.

Uses & Applications

Used extensively in construction (countertops, tiles), sculpture due to its relative softness for carving, and in powdered form as an abrasive or pharmaceutical (antacid).

Geological Facts

The Taj Mahal is constructed primarily of white marble. The small fragment in the image clearly shows the characteristic rhombohedral cleavage planes typical of calcite-rich metamorphic rocks.

Field Identification & Locations

Identify in the field by its sugary texture (saccharoidal) and its reaction to dilute hydrochloric acid (effervescence). Look for the absence of fossil remnants which differentiates it from limestone.

Identified on: 5/2/2026

Mode: Standard