ABSTRACT
The term ‘limestone’ covers a variety of geological materials that vary greatly in their origins and properties, but which can be most simply defined as sedimentary rocks made up of 50% or more of calcite and dolomite, in which calcite is the more abundant. The proportion of these combined carbonates in commercially mined high-calcium limestone is usually 90% or greater. The main criteria used in carbonate rock classifications are: • Mineral composition, meaning the percentages and types of the
carbonate minerals present (calcite, aragonite, dolomite, siderite, magnesite), and the extent to which they are mixed with noncarbonates (mainly quartz and clay minerals).
