Mohs scale of mineral hardness integrity, they are not considered "scratches" for the determination of a Mohs scale number. The Mohs scale is a purely ordinal scale. For example, corundum (9) is twice as hard as topaz (8), but diamond (10) is four times as hard as corundum. The table below shows the comparison with the absolute hardness measured by a sclerometer, with pictorial examples. On the Mohs scale, a streak plate (unglazed porcelain) has a hardness of approximately 7.0. Using these ordinary materials of known hardness can be a simple way to approximate the position of a mineral on the scale. The table below
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