Gold bars are used in numerous crafting recipes.
Gold Bars are a glossy gold color and can be obtained from Zombies in Hell, high-leveled Zombies, high-leveled Skeletons, or from a Dragon's loot. They craft some great items and are extremely helpful. Gold bars aren't very often obtained other than by mining 2 Gold ores, and aren't very frequent anywhere before the Mountain biome. Because of this, they are advised to be stockpiled.