concretion

Etymology

Borrowed from French concrétion, or Latin concretio.

noun

1. The process of aggregating or coalescing into a mass.
2. A solid, hard mass formed by a process of aggregation or coalescence.
3. (petrology) A rounded mass of a mineral, sometimes found in sedimentary rock or on the ocean floor.
   Of the three beds, the central one is the most compact, and more like ordinary sandstone: it includes numerous flattened spherical concretions. 1844, Charles Darwin, chapter 5, in Geological Observations on South America
4. The action of making something concrete or the result of such an action.
   "My new statue!" said Kenyon. . . . "It is the concretion of a good deal of thought, emotion, and toil of brain and hand." 1860, Nathaniel Hawthorne, chapter 14, in The Marble Faun