Synonyms and related words :
annealed, backed, calcified, callous, calloused, case-hardened, crusted, crusty, crystallized, fossilized, granulated, hardened, hornified, incrusted, indurate, indurated, lapidified, ossified, petrified, reinforced, rigidified, sclerotic, set, solidified, steeled, stiffened, strengthened, tempered, vitrified