Coal
From MHWiki
Coal was originally found in the unwrapping of Gifts and can now be obtained as loot in the Catacombs. The purpose of this item is unknown (much like the Onyx Stone), though it is placed under the crafting materials tab. Currently, there is no way to purchase coal.
Description
Several thousand times more dense than your average lump of coal, this carbon borders upon diamond! It's extreme density seems to give it almost... magical properties.