The trigonal crystal system is the subdivision of the crystal system that is hexagonal. It only has one difference that is minor the hexagonal system, for the reason that trigonal minerals have threefold symmetry, whereas true hexagonal minerals have actually sixfold symmetry. The crystal that is trigonal, like the hexagonal crystal system, has the following specifications:
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 an angle that is right the other corners.