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
105 George Street, The Rocks at 105 George Street, are of State heritage significance for their historical and scientific cultural values. The site and building are also of State heritage significance for their contribution to The Rocks area which is of State Heritage significance in its own right. 105 George Street is a reconstructed, typical example of a simple 19th century shop and residence. The building has been used for commercial purposes for more than 150 years. The building makes an important contribution to the surrounding 19th century commercial precinct and contributes to the character of the surrounding area of The Rocks. 105 George Street,