In Minecraft, metals such as iron and gold are only used for crafting in ingots (bars of these metals). Dalekanium, the metal which is used in the Dalek casing, can be used only in this form to craft items and tools, including armor and tools. Ingots can be obtained by killing Daleks or placing Dalekanium nuggets in and 3x3 square. For more information about Dalekanium, please see the Dalekanium page.