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
95-99 George Street, The Rocks buildings form an integral part of what was the major commercial centre of the colony, which has continued in the same use to the present day. As a group, the shops along the western side of George street have a landmark streetscape value, providing a strong architectural statement on the major entry into The Rocks. While differing in style, the buildings are sympathetic in materials and scale and form a unified visual precinct, and make a major contribution to the significance of The Rocks Conservation Area. The sites have strong associations with former uses and owners including the early penal