Corundum Ore is a reletively common ore to find. It is among the strongest elements in the game, above Diamond. Corundum tools are often used when going out on long mining adventures. But when using Corundum, you have to be very careful. DO NOT try to mine Obsidian Blocks with a Corundum Pickaxe. The pickaxe will break, and may even cause the obsidian block to explode, resulting in imediate death.
Corundum can be smelted in a furnace to create Corundum Ingot's.
With the ingot's, you can (as of the latest patch) only make a Corundum Pickaxe, a Corundum Spade, and a Cordundum Sword. There has been no word on wether or not an axe, hoe, or armor would be in the future.
Cordundum Ore is stackable up to 64.
Cordundum Ore gives off a little bit of light, similar to that of Redstone Ore.
Corundum Ore is commonly found in groups of 3-8, and in between layers 5 and 16.