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
71 Harrington Street, The Rocks and working classes in residence in The Rocks between the 1890s and the mid 1970s. The place is important in demonstrating aesthetic characteristics and/or a high degree of creative or technical achievement in New South Wales. The retained section of the house has aesthetic significance as part of a strong visual precinct forming a characteristic Rocks townscape with the adjacent terraces and the Harbour Rocks Hotel on the other side of the street. The retained street section of the former house enhances the human scale of the streetscape and reinforces the historic character of The Rocks. The item meets this