Mohs scale of mineral hardness Mohs scale of mineral hardness The Mohs scale of mineral hardness is a qualitative ordinal scale characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. Created in 1812 by German geologist and mineralogist Friedrich Mohs, it is one of several definitions of hardness in materials science, some of which are more quantitative. The method of comparing hardness by seeing which minerals can visibly scratch others is, however, of great antiquity, having been mentioned by Theophrastus in his treatise "On Stones", c. 300 BC, followed by Pliny the Elder in his "Naturalis Historia", c.
NSW Housing Board Building, Gloucester Street, The Rocks have been removed and replaced. Interior wall and floor tiling and all the sanitary fixtures have been removed. As at 30 March 2011, the NSW Housing Board Building and site are of State heritage significance for their historical and scientific cultural values. The site and building are also of State heritage significance for their contribution to The Rocks area which is of State Heritage significance in its own right. The Model Factory and Workers Dwelling at 120 Gloucester Street, The Rocks and site is of State heritage significance for its historical, aesthetic and scientific cultural values. The site and building