The stones of medieval buildings in Pisa and Lucca (western Tuscany, Italy); 3, Green and white-pink quartzites from Mt. Pisano

The chemical, mineralogical, petrographic and main physical properties of 72 green and white-pink quartzite samples from Mt Pisano have been determined. They have a 'family' likeness and are mixtures in various proportions of silica and a 'residue'; the white-pink quartzites have an average quartz content of 71.60%, somewhat higher than the green ones (64.93%). Both types are extremely resistant to degradation. The white-pink (and green) quartzites have bulk density 2.44 (2.61) g/cm (super 3) , porosity 9.40 (3.39) vol.% and grain size 344 (175) mu m. The white-pink quartzites were much more frequently used in construction work, probably due to easier quarrying.