However, if there exists a difference between the poles of the axes, then this would make the system trigonal, with a three fold principle axis, as opposed to hexagonal. In the hexagonal system there is no difference between the positive and negative poles of each a axis making a angle of only 60 degrees between the axes. These axes are symmetrically spread out to 120 degrees between the positive ends of each axis, making a six rayed star when viewed down the principle axis. The other three axes lie in a plane perpendicular to the principle axis and are labeled a 1, a 2 and a 3. The major or principle six fold axis for the hexagonal system is, of course, one of the axes. While the other systems use three crystallographic axes, the hexagonal and trigonal systems use a total of four axes. ![]() However, the hexagonal system and the similarĪre unlike any of the other five systems in terms of crystallographic axes. The hexagonal system contains classes that mirror the tetragonal system's classes with the obvious difference being the six fold axis instead of the four fold axis. The hexagonal system is uniaxial, meaning it is based on one major axis, in this case a six fold rotational axis, that is unique to the other axes. Hexagonal Pyramidal Class, 14th, 6 SOME HEXAGONAL MINERALS.Trigonal Dipyramidal Class, 15th, bar 6. ![]() ![]()
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