Quiz Flashcards
a mineral made up of platelets, a type of inorganic “dirt” formed from the decomposition of stone
clay
these clays are found closest to the area in which they formed and are generally the purest
primary
these clays are moved by water away from the formation site. these are less pure but generally more plastic
secondary
a formulation of clay made for a specific purpose and temperature range. can consist of a mixture of Kaolins, stonewares, ball clays, feldspars, etc.
clay body
the property of the material that allows it to be easily formed and retain its shape without breaking. happens due to smaller platelets in a clay and clay which is well aged and thus has gel created by bacteria that lubricates the clay platelets
plasticity
the process by which clay is changed into ceramic at high temperatures. takes place inside of a kiln
firing
unfired ceramic piece, can still be broken down in water and reclaimed
greenware
clay that has been fired once, usually in preparation for glazing. can no longer be reclaimed
bisqueware
unfired clay which is no longer soft and pliable, but not yet bone dry. can no longer be molded as drastically as wet clay, but can be more easily carved and attached via slipping and scoring. this is also the best time to apply underglazes
leather hard
clay that is completely dry and ready for a kiln firing
bone dry
a surface treatment where the surface of the clay is carved into. often the clay is painted with a layer of a different color of slip before this technique is applied
sgraffito
an indicator of the temperature of a ceramic firing, made up of clay and glaze materials placed in the kiln to be viewed through a peephole during firing
cone
clay suspended in water in a fluid consistency similar to heavy cream. used like glue when attaching wet or leather hard clay together, used with added colorants to color a surface and used with added de-flocculant in casting
slip
slips with added colorants used to “paint” the surface of clay and fired on. generally commercial colored slips are referred to as this
underglaze
a liquid mixture of colorants, clays, frits, oxides, etc. applied to the surface of a clay which when fired become vitreous and create a glass-like coating on the surface of clay. they are mostly nonporous. they do not generally fire to the same color they appear when applied. they are also more prone to running in the kiln
glaze
construction method which consists of rolling out long, cylindrical pieces of clay and slipping and scoring them together, building up in layers and smoothing the surface
coil building
construction method where the ceramicist rolls out flat pieces of clay (slabs) and then molds, cuts, and attaches these pieces to form an object
slab building
low fire fire clay, terra cotta. remains porous after firing. usually associating with iron red clays but can come in other colors as well.
earthenware
high fire, high density clay. usually grey or slightly reddish in color. often has sand or grog for structural support
stoneware
white clay bodies, often translucent when high fired. made from kaolins, with a lower plasticity than other clay bodies, often harder to form
porcelain
the process by which ceramics becomes dense and hard as particles fuse at increasing temperatures. the point at which clay will be non-porous. firing a clay beyond this point will cause it to melt
vitrification
a heavily pigmented slip comprised of small particles of clay which, when applied can create a shiny and extremely smooth surface
terra sigillata
materials which have been melted into a glass and ground to be used in glaze formulation
frit
usually oxides, these materials can lower the firing temperature of a glaze considerably by lowering its melting point
flux
