Rocks, Minerals & Ores
Mineral Sequence in the Cady Mountains
Calcite scalenohedron
CaCO3 (trigonal)Cady Mountains, Mojave Desert, CA
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Mineral Sequence in the Cady Mountains
Trigonal (crystal system)
The trigonal crystal system is really part of the hexagonal crystal system and only has one minute difference (in that true hexagonal minerals have sixfold symmetry, whereas trigonal minerals have threefold symmetry). The trigonal crystal system, like the hexagonal crystal system, has: four axes, three are equal in length and lie at an angle of 120° from each other. The fourth is either longer or shorter but must be at a right angle toward the other corners.
Minerals,net
