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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
A mineral is a naturally occurring substance, representable by a chemical formula, that is usually solid and inorganic, and has a crystal structure.It is different from a rock, which can be an aggregate of minerals or non-minerals and does not have a specific chemical composition.wo broad classes of elements are defined with regards to their contribution to a mineral's colour. Idiochromatic elements are essential to a mineral's composition; their contribution to a mineral's colour is diagnostic. Examples of such minerals are malachite (green) and azurite (blue).