Definitions for "Concretions"
Grains, pellets, or nodules of various sizes, shapes, and colors consisting of concentrated compounds or cemented soil grains. The composition of most concretions is unlike that of the surrounding soil. Calcium carbonate and iron oxide are common compounds in concretions.
Hard round, oval, or other-shaped mass of mineral or aggregate matter of varied sizes. Commonly forms by chemical precipitation around a nucleus or center, or replacement of precursor organic or inorganic material. An example is siderite (iron, calcium carbonate) concretions.