Bone china is the toughest of porcelains and does indeed contain bones. Bone ash makes up the greatest part of the formula for bone china (bone ash comes from the pulverized and burned bones of animals which are fired at temperatures of up to 1000 degrees. The resulting ash is crushed to a powder and mixed with water before being added to the other porcelain material) with the balance of the formula containing kaolin and petuntse. The resulting material is hard, resilient and an ivory white in color. It remains the standard for porcelain manufactured in England.