The Furnace is a block used to smelt ores or raw foods together to make recipes, such as turning ores into bars and cooking food.
By placing 4 blocks of basalt in a 2x2 square, you will be able to craft a furnace when used in inventory craft or using a workbench.You can purchase this for 400 gold pieces.
Fuels for the fire include coal, wooden planks, sticks and buckets of lava.