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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
Using Characteristics of Minerals to Identify Them. Most minerals can be characterized and classified by their unique physical properties: hardness, luster, color, streak, specific gravity, cleavage, fracture, and tenacity. Hardness. The ability to resist being scratchedâor hardnessâis one of the most useful properties for identifying minerals. Hardness is determined by the ability of one mineral to scratch another. Federick Mohs, a German mineralogist, produced a hardness scale (table 5) using a set of ten standard minerals.