The Seared Brick can be obtained by smelting Grout and Seared Bricks are made by four Seared Brick items in a square. Seared Bricks are used to create the Smeltery.
Seared Bricks can also be obtained by smelting Cobblestone in a Smeltery. Each cobblestone block produces 8 mB of liquid Seared Stone, so eighteen cobble blocks will produce 144 mB (1 ingot) of liquid Seared Stone. This can be poured into an ingot cast on a Casting Table to produce a single brick.