Ceramics - made of the earth, shaped with water, dried in air,
decorated and made durable by fire!
Porcelain - Developed by the Chinese "made as fine as
glass drinking cups, the sparkle of water may be seen through it ...
" wrote a 9th century traveler in Cantonese porcelain. "
. . good white porcelain, with the finest glaze. . . " wrote
Friedrich Bottger in 1709 as he discovered the secret of porcelain
production on continental Europe. The Chinese monopoly was finally
broken and the mystic behind the "white gold" was lifted.
The Courts of Europe rejoiced, but it remained unobtainable to the
general public until the beginning of the 19th Century. A typical
recipe for porcelain is 60% china clay, 20% feldspar and 20% quartz.
Bone China - In the UK the white ashes of animal bones were
ground and added to porcelain from 1748 to add strength and whiteness.
By the turn of the 19th century this became the standard English body.
Fine bone china is translucent, wear and stain resistant but less
able to withstand thermal shock compared to pure porcelain. Animal
bones have been superceded with synthetic materials. A typical composition
for bone-china is 25% china clay, 25% feldspar, 50% bone ash.
Bisque or Biscuit - Porcelain which after the initial firing
or "biscuit firing" becomes "biscuit ware" and
remains unglazed. The finish has been used on porcelain as a medium
for figurines, busts and relief work and was first used in the mid-eighteenth
century. The porcelain takes on a soft, smooth, matt appearance which
lends itself well to figurines in white and may be subsequently painted
and re-fired.
China Clay or Kaolin - A soft white natural clay
[kaolin] used with feldspar [petuntse] to produce porcelain. It has
plastic characteristics and surprisingly, is waterproof when wet and
lends itself to being moulded. During firing, the water content is
gradually reduced but retains its moulded shape. One of the major
sources of kaolin for Europe is St.Austell in Cornwall, UK.
Feldspar - A mineral geologically belonging to the silicates.
Melting at elevated temperatures it acts a flux in binding the constituents
together during firing. As the temperature drops feldspar becomes
a glass like material and contributes to the strength and translucent
properties of porcelain.
Quartz - A silicate sand, quartz is from an abundant mineral
group. Melting at elevated temperatures it reacts with feldspar to
thicken the mixture and assist in the retention of moulded shapes
by reducing distortion.
legenda:
para conhecer as convenções adotadas neste site para datação e identificação de marcas, e do tipo de produto de cada fábrica, consulte esta página, ou posicione o apontador do mouse sobre as letras dentro dos círculos ou quadrados, que a explicação aparecerá.
ATENÇÃO: Este site é o resultado de uma pesquisa pessoal sobre a história da indústria de louça no Brasil, não sou fabricante nem comerciante de porcelana, não tenho ligação ou contatos com nenhuma das marcas apresentadas, ou com qualquer outra indústria cerâmica.
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