A '''columnar''' [[Mineral Aggregates|mineral aggregate]] is made up of slender, [[parallel]] [[columns]]. [[Beryl]] is an example of a [[mineral]] exhibiting a columnar form. Chesterman, p. 40
=Sources=
*Chesterman, Charles W. ''The Audubon Society Field Guide to North American Rocks and Minerals'', Alfred A. Knopf: New York (1987)