Hardness test is Mohs scale, which is used in mineralogy. One tool to make this measurement is the sclerometer. Another tool used to make these tests is the pocket hardness tester. This tool consists of a scale arm with graduated markings attached to a four-wheeled carriage. A scratch tool with a sharp rim is mounted at a predetermined angle to the testing surface. In order to use it a weight of known mass is added to the scale arm at one of the graduated markings, the tool is then drawn across the test surface. The use of the weight and markings
121 George Street, The Rocks and has been continuously occupied for commercial and retail purposes since construction in 1880. The building's scale and alignment to the street is typical of that found along the west side of George street and lining the harbourside as part of the business precinct of The Rocks. The building is part of the rich fabric of The Rocks which is highly regarded by residents, Sydney people and visitors and acknowledged by the Australian Heritage Commission and the National Trust as part of The Rocks Urban Conservation Area. The building at 121 George street is expressive of the close weaving of