Characterization of Buner marble from Pakistan for construction purposes

The exploration and management of abundant economic mineral resources of Pakistan, particularly the vast marble deposits in the northwestern region, hold immense potential for driving economic growth. The use of marble in the construction industry faces extensive challenges such as undeveloped mining processing methods, incomplete understanding of marble qualities, undefined selection criteria for suitable varieties, and the environmentally harmful consequences of excessive waste production. This research developed a laboratory investigation protocol to characterize distinct marble deposits in Buner, Pakistan, each offering unique compositions and petrographic features. Three marble varieties were identified including pure calcitic (over ۹۰% calcite) with low silica content (۰.۱% to ۲.۵%); impure calcitic (non-carbonate minerals up to ۲۰%) with ۱۹.۸% silica and ۳۱% lime; and pure dolomite (over ۲۰% dolomite) with ۲۹% lime and ۲۳% magnesium oxide. The distinctive petrographic features of the marble deposits, such as equigranular structures, subhedral to anhedral grains, granuloblastic textures, and schistosity in impure calcitic, as well as luster-displaying dolomite in pure dolomite, provide valuable insights into their geological characteristics. Furthermore, the physical properties of the marble types exhibit correlations with their compressive and tensile strengths. Notably, the low specific gravity, water absorption, and porosity of the investigated marble result in high strength values. The average compressive strength was found to be ۳۱ MPa for pure calcitic, ۳۵ MPa for impure calcitic, and ۵۹ MPa for pure dolomite marble. Likewise, the tensile strengths measured ۶ MPa, ۷ MPa, and ۹ MPa, respectively. While the investigated marble types prove to be excellent choices for dimension stone applications, it is crucial to note that they do not meet the standards required for cement production and paint manufacturing. This research contributes to the understanding of Pakistan's marble resources, refined processing methods, and sustainable construction practices.

Keywords:

Petrographic features , geochemical characteristics , Mechanical properties , marble deposits