圧し石[oshiishi] stone weight
一石[isseki] one game (of go)
一石二鳥[issekinichou] killing two birds with one stone
英国石油[eikokusekiyu] British Petroleum
下石[shitaishi] nether millstone

化粧石鹸[keshousekken] toilet soap
化石[kaseki] fossil
化石学[kasekigaku] paleontology
化石層[kasekisou] fossil bed
化石燃料[kasekinenryou] fossil fuel

丸砥石[marutoishi] grindstone
合わせ砥[awasedo] double whetstone
青砥[aoto] medium-grade millstone
中砥[nakato] medium-grade millstone
剃刀砥[kamisorido] razor strop

砥石[toishi] whetstone
砥ぐ[togu] to sharpen
油砥石[aburatoishi] oilstone
荒砥[arato] rough grindstone
砥粉[tonoko] polishing powder