A '''mammillary''' [[Mineral Aggregates|mineral aggregate]] forms smooth, rounded masses. [[Hematite]] is an example of a [[mineral]] exhibiting a mammillary 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)