|Blast Furnace Brick|
Blast furnace brick is used to make blast furnaces. You need 34 to make one blast furnace. They are made from soul sand, nether bricks, and magma cream with the optional intermediate step of infernal bricks.
Note: These bricks periodically check to see if they form a complete blast furnace. Using many of them for decoration will cause lag. Using infernal bricks is recommended.