Clay, pottery, earthenware, terracotta, stoneware – are they all the same
Clay is essentially the raw material. It is a mix of mineral substances
that occur in sedimentary rocks and soils. It is soft when moist, but hardens
when heated. Item made from clay become earthenware when it is fired at
relatively low temperatures (where it does not become vitreous).
Pottery comprises three
distinctive types of wares: earthenware, stoneware, and porcelain.
The first type, earthenware, has been manufactured using the same
basic techniques since ancient times. Earthenware is basically composed of clay
or a blend of clays that are baked firm. Because it is fired at low heat, the
pottery clay does not lose its porous nature and does not become translucent.
Earthen wares are porous and therefore not as strong as stone wares. Earthenware
can be glazed, but it will never be as hard as stoneware-glazed surface. An
earthenware-glazed dish will scratch or chip more easily than the harder surface
The second type of pottery, called stoneware is earthenware relatively rich
in vitreous material and fired at so high a temperature (about 2185 degrees
Fahrenheit) that it becomes as hard as stone and non-porous. Stoneware is
extremely strong and will not absorb water. Because stoneware is nonporous, it
does not require a glaze; when a glaze is used, it serves a purely decorative
function. Stoneware dishes can
be used in conventional and microwave ovens.
Porcelain was invented by the Chinese and consists of feldspathic
material incorporated in a stoneware composition. Porcelain is a very hard white
ceramic which has been manufactured in China since the 600s, and in Europe since
the 1700s. Porcelain, also called china, is fired using very high heat,
resulting in a white, nonporous pottery. Porcelain is translucent;
stoneware and earthenware is not.
Terracotta is an Italian word for “baked earth”. It refers to type of
brownish, unglazed porous earthen wares.