セキ、シャク、コク
いし
石, 口
石
stone
"石油(せきゆ): oil; petroleum; kerosene
化石(かせき): fossil; petrifaction; fossilization; fossilisation
石炭(せきたん): coal
宝石(ほうせき): gem; jewel; precious stone
磁石(じしゃく): (1) magnet (2) compass
岩石(がんせき): rock
石鹸(せっけん): soap
石(いし): (1) stone (2) gem; jewel
流石(さすが): (1) as one would expect (2) still; all the same (3) even... (e.g. ""even a genius..."")"