Common Clay and Glaze Materials
Alumina Hydrate - calcined form of alumina, used in glazes ad on kiln shelves
Ball Clay – A plastic secondary clay, high firing and white or whitish in color
Barium Carbonate - a glaze flux. I don’t use this in my studio due to it being a toxic material
Bentonite- a clay, often as a plasticizer in clay. Also used in glazes and to prevent settling
Bone Ash(Calcium Phosphate) - a glaze flux, large amounts in glazes can cause pinholing
Clay or Clay Body - a decomposed feldspathic rock from which a pottery is made
Cobalt Carbonate - blue colorant used in glazes, melts with less speckling than cobalt oxide
Cobalt Oxide - blue colorant used in glazes, extremely strong color, can have speckling
Copper Carbonate - green colorant used in glazes, melts evenly into glaze
Copper Oxide - green colorant
Cornwall Stone - clay and glaze ingredient
Feldspar - glaze flux, also used in clays
Fireclays – high temp clays with high percentage of fluxes
Gerstley Borate - used in glazes, gives a slight opalescent color
Ilemenite - creates dark specks in glazes
Iron Oxide ferric oxide, ferrous oxide) - used in clay, glazes, slips and for brushwork
Kaolin (china clay) - used in clays and glazes, fires to a pure white, I use EPK in my studio
Lead (all forms) - toxic material used in glaze, produces rich, vibrant colors
Magnesium Carbonate - a glaze flux, can be used to make intentional “crawl” effects
Magnesium Sulfate (Epsom salt) - used as a flocculent (thickener) in glaze containing clay
Manganese Oxide - a colorant, used in glazes, produces browns
Nepheline Syenite – sub for potash feldspar, can lower the melting point of a glaze
Nickle Oxide – glaze colorant, available in black or green
Rutile – a tan glaze colorant, impure form of titanium dioxide, promotes crystalline surfaces
Silica (Flint or Quartz)- used in glazes as a glass former and in clays
Sodium Silicate – a deffoculant
Spodumene – a glaze and clay ingredient
Talc – clay and glaze ingredient, used in whiteware bodies
Titanium Oxide or Dioxide – used in glazes, an opacifier, promotes crystal growth
Whiting (calcium carbonate)- used in clay and glazes, a glaze flux
Wollastonite – a clay and glaze ingredient, promotes clear transparent glazes
Zinc Oxide – used in glazes, as a flux, an opacifier, promotes high gloss and vibrancy
Zircopax – an opacifier, a commercially produced glaze ingredient