PHASE, MICROSTRUCTURE AND MECHANICAL PROPERTIES OF MARBLES IN NORTH- WESTERN PART OF PAKISTAN: PRELIMINARY FINDINGS

Marbles are widely used in construction industry due to their strength and variety of colours. The North West Frontier Province (NWFP) of Pakistan has enormous marble deposits and is therefore of immense economical significance. Super-white, Sunny-grey and Silky-black marble samples are comprised of calcite along with quartz whereas the Nowshera-pink marble contains dolomite in addition to the calcite and quartz. The sunny-grey marble had more strength as compared to the others although the final fracture in the Nowshera pink marble also occurred at the same maximum force but many times fracture were also occurring at lower forces. Fracturing at lower forces may be due to cracks already developed during extraction through blasting or thermo-mechanical history of the rocks.