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
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