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
Our Lady of the Rocks long journey, and eventually, she became blind. She used golden and silver fibres but what makes this tapestry so famous is the fact that she also embroidered her own hair in it. Our Lady of the Rocks Our Lady of the Rocks (, ) is one of the two islets off the coast of Perast in Bay of Kotor, Montenegro (the other being Sveti Đorđe Island). It is an artificial island created by bulwark of rocks and by sinking old and seized ships loaded with rocks. The Roman Catholic Church of Our Lady of the Rocks () is the largest