What is another word for "hardness"?

Roget's Thesaurus (1911) lists these synonyms for "hardness": adamant, adamantean, adamantine, adder, and, beetle, benefit, block, board, bone, bony, brick, buckram, calculous, callosity, cartilage, cartilaginous, cast, cement, clergy, close, concrete, conscience, contrition, corneous, crag, crystal, crystallization, deaf, deaf-mute, deafen, deafness, deal, die, dull, durity, ear, earless, evil, firm.