Berkshire coffee cup demitasse

Bone china

Bone china is a kind of porcelain body first produced in the United Kingdom in which calcined ox bone, bone ash, is an important part. It is distinguish by supreme whiteness, strength and translucency. berkshire coffee cup/demitasse may be an example of this process.

The initial use of bone ash in ceramics is credited to Thomas Frye in 1748 in which he used it to make a type of soft-paste porcelain. In In the late 18th century, Josiah Spode carried on with further developments, and subsequently popularized it, by combining it with china clay, kaolin and China stone to compete with the imported Oriental porcelain.

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

The manufacture of bone china customarily employs a two stage firing process where the first "biscuit" is fired without a glaze at 1280