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In addition, it must be hard and durable. Its value increases if it is also rare.The beauty of a gem is measured in terms of its clarity, brilliance, and color. Comments
Other Identifying Characteristics [edit]. Minerals have some other properties that can be used to identify them. For example, a mineral's crystal structure can be used to help identify the mineral. Sometimes, a trained mineralogist can tell the crystal structure just by looking at the shape of the mineral. mineral is more likely to break where the bonds between the atoms are weaker. Cleavage is the tendency of a mineral to break along certain planes to make smooth surfaces. Minerals with different crystal structures will cleave in different ways, as Figure 3.16 shows.