FURNACE

A Furnace is used to heat blocks and turn them into other items. Furnaces are considered one of the fundamental blocks required to advance in Survival mode. Furnaces can naturally occur in NPC villages. Before the furnace appeared, smelting was accomplished by creating a fire and dropping the ores into it. Furnaces are currently available in all versions of Minecraft except for Classic.The furnace, when right-clicked, has its own menu where heating operations can be done. It consists of one field for the object that will be smelted, one field for the fuel and one field for the output object.

Wood, wooden planks, wooden pressure plates, coal, charcoal, blaze rods and lava buckets (plus chests, crafting tables, bookshelves, sticks, saplings, jukeboxes, note blocks, locked chests, wooden stairs, trapdoors and fences, none of which are very efficient) are all fuels. Each smelting operation takes 10 seconds. Furnaces resemble dispensers, but the two blocks have different uses and crafting recipes.

Smelting will continue to work when the smelting menu is closed, as long as there are still objects to heat and there is enough fuel. The fire icon diminishes to represent the fuel burn time. When the fire icon diminishes fully, another fuel item is consumed and the heat is refilled. If all objects are smelted, the furnace will stop using additional fuel. The furnace will also stop if the output field contains a full stack, or if it contains a different item (e.g., trying to smelt gold ore with iron ingots in the output). If there is no fuel left, the furnace will become inactive. If a smelting process was running, it will be cancelled and must be redone.

Gold and iron ores can be smelted into ingots. Furnaces can also be used to smelt redstone ore, lapis lazuli ore, coal ore, and diamond ore (obtained with the Silk Touch enchantment) and returns 1 redstone, lapis lazuli, coal, or diamond respectively.

When the items smelted in a furnace are collected, they drop experience orbs equal to the number of items in the stack. This makes furnaces a reliable (if slow) early source of experience. (As of prerelease 12w22a)

Fuel	Burning Time	Number of Operations per Fuel	Amount to Light a Furnace All Night	Seconds per Wood Block (log)[fn 1]	Amount needed to burn a stack (64) of items
Coal	80s	8	6.75	-	8
Charcoal	80s	8	6.75	up to 69s[fn 2]	8
Wood	15s	1.5	36	15s	43
Wooden Planks	15s	1.5	36	60s	43
Wooden Slabs	7.5s	0.75	48	60s	86
Saplings	5s	0.5	108	-	128
Tools and Weapons	10s	1	54	5s to 10s	64
Wooden Pressure Plate	15s	1.5	36	30s	43
Stick	5s	0.5	108	40s	128
Fence	15s	1.5	36	40s	43
Wooden Stairs	15s	1.5	36	40s	43
Trapdoor	15s	1.5	36	20s	43
Crafting Table	15s	1.5	36	15s	43
Bookshelf	15s	1.5	36	10s	43
Chest	15s	1.5	36	7.5s	43
Jukebox	15s	1.5	36	7.5s	43
Note Block	15s	1.5	36	7.5s	43
Huge Brown Mushroom	15s	1.5	36	-	43
Huge Red Mushroom	15s	1.5	36	-	43
Blaze Rod	120s	12	4.5	-	5.3
Lava Bucket	1000s	100	0.54	-	0.64