Mohs scale of mineral hardness integrity, they are not considered "scratches" for the determination of a Mohs scale number. The Mohs scale is a purely ordinal scale. For example, corundum (9) is twice as hard as topaz (8), but diamond (10) is four times as hard as corundum. The table below shows the comparison with the absolute hardness measured by a sclerometer, with pictorial examples. On the Mohs scale, a streak plate (unglazed porcelain) has a hardness of approximately 7.0. Using these ordinary materials of known hardness can be a simple way to approximate the position of a mineral on the scale. The table below
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