Charrite

Charrite is a very brittle metal which heats up but doesn't cool down. It is also a more powerful version of coal. However, the charrite ore has to be smelted into ingots in order to function. When placed in the bottom slot of the furnace, it lasts 18 uses, 10 more then normal coal. It can be used to make torches, but it makes 12 of them instead of the normal 4. It is rare, but can be found at any layer. It can be used to create Pyregold, and used in any recipe replacing coal. You can also use blaze rods and charrite to create charrite torches, which gives a light level of 15, works in your hand, and even underwater.