瓦礫[gareki] rubble
砂礫[sareki] pebbles
紙礫[kamitsubute] paper pellet
梨の礫[nashinotsubute] not getting a reply
飛礫[tsubute] stone thrown at somebody

礫岩[rekigan] conglomerate stone
火山礫[kazanreki] lapilli
雪礫[yukitsubute] snowball
闇夜の礫[yamiyonotsubute] aimless attempt