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
123-125 George Street, The Rocks Free Classical style, executed to give a sense of decorum to what would otherwise have been simple commercial / residential structures. The buildings have streetscape value as two buildings in a group of three that were designed to appear as one property. The buildings' scale and alignment to the street are typical of that found along the business precinct of George Street in The Rocks area. The street façades have remained relatively intact since they were constructed in 1882. The place has a strong or special association with a particular community or cultural group in New South Wales for social,