Oil of Brick (3.5e Equipment)
From D&D Wiki
 Oil of Brick
Oil of Brick is created by heating pieces of brick to red-hot temperature, and then quenching them in a vessel of olive oil. The brick absorbs the oil, and is then placed in a retort and heated so as to create a distillate of the oil drawn from the brick. Oil of Brick is also known as the Oil of Philosophers.
Oil of Brick can be created with the proper materials and a successful Craft (Alchemy) check (DC 10).
Topical application or ingestion grants a +1 alchemical bonus to Heal checks to cure tumors or growths. Using a flask or vial of Oil of Brick grants a +1 alchemical bonus to Craft (gem cutting) or Profession (gem cutting) checks.
One vial costs 20 gp and weighs 1 lb.
Wikipedia: Oil of Brick