c axis[′sē ‚ak·səs]
A vertically oriented crystal axis, usually the principal axis; the unique symmetry axis in tetragonal and hexagonal crystals.
The reference axis perpendicular to the plane of movement of rock or mineral strata.
The angle that specifies the rotation of a machine tool about the z axis.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.