Zonal

[Sarah]

Of or pertaining to a zone; having the form of a zone or zones.Zonal equation (Crystallog.), the mathematical relation which belongsto all the planes of a zone, and expresses their common position withreference to the axes.-- Zonal structure (Crystallog.), a structure characterized by thearrangements of color, inclusions, etc., of a crystal in parallel orconcentric layers, which usually follow the outline of the crystal,and mark the changes that have taken place during its growth.-- Zonal symmetry. (Biol.) See the Note under Symmetry.