High-Grade Limestones in Austria

High-grade limestones are sedimentary or metamorphosed rocks (marbles) which consist mainly of calcite (rarely aragonite) and contain at least 75 % calcium carbonate.

Map of high-grade limestones in Austria
High-grade limestones in Austria.
© Geological Survey of Austria

While ordinary limestones are widely abundant, those qualifying for industrial minerals are much less common.

Stack of pure white paper
High brightness values ​​are in demand for carbonate fillers in the paper industry.
© Geological Survey of Austria / Andreas Ortag

They must contain > 98 % calcium carbonate and display a purely white colour (> 90 % luminance). They were mostly deposited in environments far from land (e.g. reefs) or metamorphosed. As raw materials, they are used for many industrial processes and technical products.