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
Orient Hotel, The Rocks of The Rocks under SCRA erupted in 1973 in organised community protests supported by the NSW Branch of the Builders Labourers' Federation. By 1975, SCRA's planning outlook had evolved to take into consideration cultural, social and historical values, but large scale developments continued. The Orient Hotel with its corner location and historic street presentation has contributed to the public's association of The Rocks with a unique historic neighbourhood. Around 1976, a company named Rocks Hotels Pty Ltd. took on the management of the hotel and in 1979 extensive alterations valued at $120,000 were completed to provide street facades approximating its