Sandon coffee saucer

Bone china

Bone china is a type of porcelain body originally produced in the United Kingdom in which calcined ox bone, bone ash, is a major ingredient. It is differentiated by brilliant whiteness, strength and translucency. sandon coffee saucer may be an example of this procedure.

The initial use of bone ash in ceramics is attributed to Thomas Frye in the mid eighteenth century in which he used it to introduce a kind of soft-paste porcelain. In Towards the end of the eighteenth century, Josiah Spode undertook further developments, and duly made it popular, by combining it with kaolin, China stone and china clay to compete with the imported Oriental porcelain.

The initial elementary formula of four parts china stone, three and a half parts china clay, and six parts bone ash still remains the standard English body.

The production of bone china commonly uses a two stage firing process where the first "biscuit" is fired without a glaze at 1280