Bone china is a type of porcelain that is composed of bone ash, feldspathic material and kaolin. It has been defined as ware with a translucent body containing a minimum of 30% of phosphate derived from animal bone (Prouna products are made with over 50% bone ash) and calculated calcium phosphate. Developed by English potter Josiah Spode, bone china is known for its high levels of whiteness and translucency, and very high mechanical strength and chip resistance.
The first development of what would become known as bone china was made by Thomas Frye at his Bow porcelain factory near Bow in East London in 1748. His factory was located very close to the cattle markets and slaughterhouses of Essex, and hence easy access to animal bones. Frye used up to 45% bone ash in his formulation to create what he called ‘fine porcelain.’ Although in quality it rivalled porcelain imported from Europe and China the factory was not a commercial success.
Later, Josiah Spode in Stoke further developed the concept, and finalised his formulation sometime between 1789 and 1793. Amongst his developments was to abandon Frye’s procedure of calcining the bone together with some of the other body raw materials, instead calcining just the bone. Bone china quickly proved to be highly popular leading to it being introduced by other English pottery manufacturers.
Excerpt taken from Wikipedia