Hearth blocks are blocks which can be crafted or found in various structures containing fireplaces, such as taverns, mead halls, houses, as well as on the top of obelisks.
This block shares the properties of netherrack in that a fire lit on one will never burn out, making them a useful and easily obtainable alternative for creating fireplaces while in Middle-earth.
The recipe for three hearth blocks requires three coal (normal or charcoal) and three bricks on a vanilla crafting table.
Hearth blocks in the fireplace of a tavern
Hearth blocks in the fire pit of a house