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.
93 George Street, The Rocks development of The Rocks. The site has scientific significance for the archaeological potential to reveal evidence of road surfaces and earlier buildings on the site. The building is socially significant for its long history, and for its contribution to The Rocks area, Australia's premier heritage precinct. Shop, Zia Pina Pizzeria was listed on the New South Wales State Heritage Register on 10 May 2002 having satisfied the following criteria. The place is important in demonstrating the course, or pattern, of cultural or natural history in New South Wales. The site of 91 and 93 George Street is historically significant as