Individual, [[spheroid]]al [[sedimentary rock|sedimentary]] grains from which '''oolitic''' [[rock]]s are formed. Usually [[calcerous]] with a [[concretic]] or [[radial]] structure.
Pellant, p. 251
=Sources=
*Pellant, Chris. ''The Complete Book of Rocks and Minerals'', Dorling Kindersley Inc.: New York (1995)