BONE CHINA A smooth textured and extremely white firing pottery body. Translucent and very strong. It is unique in that it contains a high proportion of calcined bone ash and biscuit fires at approx 1220 C. A type of porcelain.
Around fifty percent of the body recipe contains calcined cattle bones. Invented at the Spode factory in Stoke-on-Trent around 1800. The recipe contains about 50% calcined cattle bone, 25% china clay and 25% china stone. The bone used at Spode was more specifically the shins and knuckle bones of oxen. (Lower grades of bone china, not from Spode, may have used all or some bones from sheep or goats. But definitely not horses.) The bones are calcined at temperatures up to 1000 C before being ground to a fine powder and used in the bone china recipe. Bone china is extremely hard and intensely white.
Bone China: a Particularly English Porcelain
The Invention of Bone China: The Spode company, under Spode I and Spode II, is credited by potters, collectors, researchers and other experts with having perfected the bone china formula before 1800.