Synonyms for Concretion:

n.

clotting (noun)
coagulation.
concretion (noun)
coalescence, calculus, coalition, densification, compression, conglutination, coalescency, compaction.
crystallization (noun)
coalescence, coagulation, consolidation, solidification, concentration.
gallstone (noun)
calculus.
solidification (noun)
solidification.

v.

hardening (verb)
solidification.

Other synonyms:

clotting
coagulation.
Other relevant words:
coagulation, solidification, consolidation, concentration.