Stone

硝 nitrate, saltpeter N1 礁 reef, sunken rock N1 硫 sulphur N1 碑 tombstone, monument N1 磁 magnet, porcelain N1 碁 Go N1 砕 smash, break, crush N1 砲 cannon, gun N1 礎 cornerstone, foundation stone N1 磨 grind, polish, scour N2 砂 sand N2 硬 stiff, hard N2 石 stone N3 研 polish, study of, sharpen N4 破 tear, break N2 確 certain, confirm N2