Mohs scale of mineral hardness incorporates additional substances that may fall between levels: Comparison between hardness (Mohs) and hardness (Vickers): 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
95-99 George Street, The Rocks buildings form an integral part of what was the major commercial centre of the colony, which has continued in the same use to the present day. As a group, the shops along the western side of George street have a landmark streetscape value, providing a strong architectural statement on the major entry into The Rocks. While differing in style, the buildings are sympathetic in materials and scale and form a unified visual precinct, and make a major contribution to the significance of The Rocks Conservation Area. The sites have strong associations with former uses and owners including the early penal