Block of Cobalt is a block added by Tinkers' Construct. Block of Cobalt is primarily used as a storage block for Cobalt Ingots but may also be used as decoration.
Block of Cobalt cannot be crafted like vanilla Minecraft material blocks, but must be crafted by pouring 1296mB (9 ingots) of Molten Cobalt in a Casting Basin from a Smeltery.
They may be broken down by the use of a Crafting Table to produce 9 Cobalt Ingots. With 4 Blocks of Cobalt a Cobalt-legged version of the Tool Forge can be crafted, which is purely aesthetic.