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.
105 George Street, The Rocks at 105 George Street, 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. 105 George Street is a reconstructed, typical example of a simple 19th century shop and residence. The building has been used for commercial purposes for more than 150 years. The building makes an important contribution to the surrounding 19th century commercial precinct and contributes to the character of the surrounding area of The Rocks. 105 George Street,