Minerals are defined by five criteria: 1. Naturally Occurring, 2. Inorganic, 3. Solid, 4. Defined Chemical (Atomic) Formula, and 5. A unique set of physical properties.
-are compounds in which metallic elements combine with halogens (the elements chlorine, bromine, fluorine and iodine). Halides are common in a number of geological environments. Some, such as halite, are found in the evaporite seqience.
Raw Banded Fluorite
Sliced Banded Fluorite
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Data: Pellant, Chris. Smithsonian Handbooks: Rocks and Minerals, The clearest recognition guides avaiable. A Dorling Kindersley Book.