Heirloom cream soup cup

Bone china

Bone china is a type of porcelain body initially developed in Great Britain in which calcined ox bone, bone ash, is an important ingredient. It is distinguish by extremely high whiteness, translucency and strength. heirloom cream soup cup may be an example of this process.

The initial use of bone ash in ceramics is attributed to Thomas Frye in the mid eighteenth century in which he used it to develop a kind of soft-paste porcelain. In At the close of the eighteenth century, Josiah Spode carried on with further developments, and duly popularized it, by mixing it with China stone, kaolin and china clay to compete with the imported Oriental porcelain.

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

The manufacture of bone china consistently uses a 2 stage firing process where the first "biscuit" is fired without a glaze at 1280°C (2336°F) giving a semiopaque product and then it is glaze, or glost, fired at a lower temperature less than 1080°C (1976°F). heirloom cream soup cup is probably made using this method.

Soft-paste porcelain

Soft-paste porcelain is a type of porcelain and therefore a ceramic product.

Its history dates from the initial exertions by potters from Europe to imitate Chinese porcelain by using formulations of china clay and ground-up glass (aka frit); lime and soapstone were also known to have been added in some compositions. As these early compounds suffered from high pyroplastic collapse, or slumping in the kiln at raised temperature, it was uneconomical to produce them. Mixtures were later produced based on nepheline syenite, kaolin, quartz, feldspars and other feldspathic rocks. These were technically superior and continue in production to this day.

Hard-paste porcelain

Hard-paste porcelain is a hard, dense ceramic that was originally produced from a compound of the feldspathic rock petuntse and kaolin fired at extremely high temperature. It was first manufactured in China in around the 9th century.

The secret of its manufacture was not known in Europe until the early 18th century, when Böttger of Meissen, Germany uncovered the formula. Regardless of attempts to keep it secret, the procedure was used by other German ceramic factories and eventually became known throughout Europe.

Hard-paste porcelain is fired at a range of temperatures to make many individual end results. Depending on the firing process, hard-paste porcelain can be made to resemble stoneware or earthenware. Generally however, it is not necessary to utilize hard-paste porcelain for such lower temperature ceramics. Hard-paste porcelain can be utilized to manufacture porcelain bisque, a hard crystalline material fired at very high temperatures in a pressure controlled environment. This approach gives birth to a semitransparent bright white ceramic. Unlike other bisque ceramics, porcelain bisque is almost inpenetrable by water, making it unnecessary to glaze the body before decorating. Manufacturers such as Hummel, Precious Moments and Lladro make use of hard-paste porcelain just for this reason, this could include heirloom cream soup cup.