stoneware- definition,characteristics, types,

1. STONEWARE
PRESENTATION BY
KIRTHIGA.E
ABINAYA.P
SANDHYA.P
MOHANA PRIYA.S
SUBHASHREE.

2. STONEWARE
• Stoneware is a vitreous or semi-vitreous ceramic made primarily
from stoneware clay or non-refractory fire clay.
• Stoneware is fired at high temperatures and cooled down slowly
• It is nonporous and so does not need a glaze
Definition:
The term stoneware is used to indicate the
wares or articles prepared from refractory
clay which are mixed with stone and crushed
pottery .

3. • Matures between 1200-1300 ̊ C
(2192-2372 ̊ F). High fired!
• Hard, dense clay body which has a water
absorption rate of 3% or less when fully fired
• It is usually coloured grey or brownish because of
impurities in the clay used for its manufacture,
and is normally glazed.“
• Colors can be off-white, tan, grey and/or brown
• Often used for “art pottery”: jugs, mugs, plates,
bowls, etc.

4. • The key raw material in stoneware is either
naturally occurring stoneware clay or non-
refractory fire clay.
• The mineral kaolinite is present but
disordered, and although mica and quartz are
present their particle size is very small.
• Stoneware clay is often accompanied by
impurities such as iron or carbon, giving it a
"dirty" look, and its plasticity can vary widely.
• Non-refractory fire clay may be another key
raw material.

5. • Fire clays are generally considered refractory,
because they withstand very high
temperatures before melting or crumbling.
• Refractory fire clays have a high concentration
of the mineral kaolinite, with lesser amounts
of mica and quartz.
• Non-refractory fire clays, however, have larger
amounts of mica and feldspar.

6. • STONEWARE clays are abundant in nature,
although less plentiful than terra cotta
deposits.
• Usually stoneware clays are
blended
• Stoneware clays are similar
to fire clays, but more
plastic and less refractory.
• Sound- clear ringing sound when struck each
other

7. • Stoneware clays have an absorption factor of
about 2 to 5 percent, and are usually fired to
temperatures ranging from 2100 degrees to
2372 degrees F (cone 3-cone 11*).
• As one might guess, stoneware clays are so
named because the fired wares exhibit stone-
like characteristics:
• a hard,
• dense surface with often variegated color.

8. • Stoneware usually bonds well with its glazes, and
should be completely leak-proof after firing to
maturity.
• It is tough and forgiving during throwing and
firing stages, and is often used for industrial
ceramics.
• Fired stoneware can yield pleasing colors ranging
from buff or light gray to brown or dark gray.
• Because of its hard, tight qualities, this clay is an
excellent choice for functional applications,
especially dinnerware.
• The higher the maturing temperature of the
stoneware, the more durable the product.

9. GOOD BODY CHARACTERISTICS:
• Good plasticity for forming method but with enough
tooth to make large shapes w/o slumping.
• Body open enough to dry w/o undue warping or
cracking.
• Shrinkage controlled in drying and firing: no tendency
to cracking.
• Does not warp or slump much in firing to maturity
• Desired degree of vitrification
• Color desired
• Freedom from alkalies (soluble salts) that cause
scumming.

10. TYPES OF STONE WARE
• Traditional stoneware
• Fine stoneware
• Chemical stoneware
• Thermal shock resistant stoneware
• Electrical stoneware

11. Traditional stoneware
• a dense and inexpensive
body.
• It is opaque, can be of any
colour and breaks with a
conchoidal or stony fracture.
• Traditionally made of fine-
grained secondary, plastic clays
which can used to shape very
large pieces.

12. • FINE STONEWARE –
• made from more carefully selected,
prepared, and blended raw materials.
• It is used to produce tableware and art ware.
• CHEMICAL STONEWARE –
• used in the chemical industry, and when
resistance to chemical attack is needed.
• Purer raw materials are used than for
other stoneware bodies.
• Ali Baba is a popular name for a large
chemical stoneware jars of up to 5,000 litres
capacity used to store acids.

13. • THERMAL SHOCK RESISTANT STONEWARE –
has additions of certain
materials to enhance the
thermal shock resistance of the
fired body.
• ELECTRICAL STONEWARE –
historically used for electrical
insulators,
although it has been replaced by electrical
porcelain.

14. STONEWARE IN ARCHITECTURE

15. • Formulations for stoneware vary considerably,
although the vast majority will conform to:
• plastic fire clays, 0 to 100 percent;
• ball clays, 0 to 15 percent;
• quartz, 0 to 30 percent;
• feldspar and chamotte, 0 to 15 percent.