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Lizella Clay

CLAY

Alternate Names: Lizzella, Lizzela

OxideAnalysisFormula
CaO0.50%0.043
MgO0.80%0.097
K2O1.30%0.067
Na2O0.60%0.047
TiO21.10%0.067
Al2O320.90%1.000
SiO259.10%4.799
Fe2O35.00%0.153
LOI10.50
Oxide Weight435.82
Formula Weight486.95
If this formula is not unified correctly please contact us.

A red burning clay from Lizella, Georgia (raw color is light green). It is available from Davens or Kickwheel Pottery Supply.

This material is sometimes cited as a substitute for Redart in bodies, but such is not the case. Compared to Redart, it has a higher drying shrinkage (6.5% vs. 5.5%), it is more plastic (thus more prone to cracking during drying) and the iron content is lower (5% vs. 7%). As far as fired maturity, these materials are not even close. At cone 4, for example, Lizella has around 11% porosity vs. almost zero for Redart, and 4% fired shrinkage vs. 8% for Redart. Lizella stays stable all the way to cone 10 oxidation (where it has about 3% porosity and 6% fired shrinage and fires deep red).


Redart (left) vs. Lizella clay. Definitely not substitutes for each other.

These bars have been fired at cones 4, 2, 02, 04 (top to bottom). The Redart is much more vitreous and reaches almost zero porosity by cone 4 whereas the Lizella still has 11% porosity at cone 4. Lizella also has a much higher drying shrinkage because it is way more plastic. Two red clays could not be much more different than these yet sometimes they are substituted for each other in recipes!

Out Bound Links


By Tony Hansen

XML for Import into INSIGHT

<?xml version="1.0" encoding="UTF-8"?> <material name="Lizella Clay" descrip="CLAY" searchkey="Lizzella, Lizzela" loi="0.00" casnumber="70694-09-6"> <oxides> <oxide symbol="CaO" name="Calcium Oxide, Calcia" status="" percent="0.500" tolerance=""/> <oxide symbol="MgO" name="Magnesium Oxide, Magnesia" status="" percent="0.800" tolerance=""/> <oxide symbol="K2O" name="Potassium Oxide" status="" percent="1.300" tolerance=""/> <oxide symbol="Na2O" name="Sodium Oxide, Soda" status="" percent="0.600" tolerance=""/> <oxide symbol="TiO2" name="Titanium Dioxide, Titania" status="" percent="1.100" tolerance=""/> <oxide symbol="Al2O3" name="Aluminum Oxide, Alumina" status="" percent="20.900" tolerance=""/> <oxide symbol="SiO2" name="Silicon Dioxide, Silica" status="" percent="59.100" tolerance=""/> <oxide symbol="Fe2O3" name="Iron Oxide, Ferric Oxide" status="" percent="5.000" tolerance=""/> </oxides> <volatiles> <volatile symbol="LOI" name="Loss on Ignition" percent="10.500" tolerance=""/> </volatiles> </material>


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