Cornerstones rhymes with:
waterstone's, blackstone's, bridgestone's, cherrystones, cobblestones, firestone's, flagstones, folkstone's, gallstones, gemstones, gladstones, gravestones, hailstones, headstones, keystone's, keystones, limestones, livingstone's, madstones, milestones, moonstones, redstone's, rhinestones, tombstones, waterstone's, yellowstone's