Minecraft wiki entry for Achievement_guide, associated text: Look in various loot chests or search below layer 16 for diamond ore (layer 5-12 is also good, layer 12 is the best; press F3 to see your coordinates) and destroy it using your iron pickaxe. Creeper or TNT explosions have a chance of dropping the diamond as well. Mineshafts are extremely useful for this achievement. Arrange the ingredients like so to craft an iron pickaxe: