KEY POINTS IN THIS CHAPTER •
Minerals must satisfy certain criteria to be called minerals. They must be inorganic.
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Minerals form a specific crystalline shape, based on their chemistry.
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Minerals have specific identifiers, such as color, density, hardness, luster, and cleavage.
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The Mohs hardness scale is used to tell the hardness of minerals in the field. It is a linear scale from 1 to 10, with 10 being attributed to diamonds.
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Minerals are either silicates or nonsilicates. Silicates are more common and are made from some combination of silicon and oxygen in tetrahedral shape.
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Nonsilicate materials occur in many kinds, mostly as salts of varying kinds. Ores are made from metals and are used to extract many precious metals.
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