Gold Nugget
From The Blockheads Wiki
Gold is the rarest Ore in the game. You can use it to make a level 3 furnace which is used to make Gold Ingots, from there you can use it to make to make a level 6 Tool Bench or Gold Blocks. With a level 6 Tool Bench now in hand you can use it to make a Gold Spade or Gold Pickaxe.