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Hectorite

Hectorite

Formula: Na0:3(Mg; Li)3Si4O10(OH)2

OxideAnalysisFormula
CaO0.35%0.009
Li2O1.20%0.055
MgO25.50%0.868
K2O0.15%0.002
Na2O3.00%0.066
Al2O30.35%0.005
SiO253.75%1.226
H2O14.40
Cl0.30
Oxide Weight115.60
Formula Weight135.52
If this formula is not unified correctly please contact us.

Hectorite - (Mg,Li)3 Si4O10 (OH)2 Na0.3 (H2O)4 is lithium magnesium sodium montmorillonite (bentonite is largely sodium calcium magnesium montmorillonite). Typically hectorite contains much less iron and titanium than bentonite and contains almost no alumina (being essentally a hydrated silicate). In addition it is very high in magnesia compared to other clays.

While 1-2% iron content in regular bentonite has minimal effect on fired whiteness, tiny amounts of titanium do affect translucency, making otherwise white ware look grey. This is attributed to fibrous rutile crystals in the porcelain matrix. In addition, titanium can react with any iron present to produce Fe/Ti spinel which is intensely black in colour.

The purest kaolins are also the least plastic, plastic ball clays are high in Fe/Ti. This makes hectorite an interesting material for the best white porcelain.

Analysis from Handbook of Mineralogy, 2001.


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By Tony Hansen

XML for Import into INSIGHT

<?xml version="1.0" encoding="UTF-8"?> <material name="Hectorite" descrip="Hectorite" searchkey="" loi="0.00" casnumber="12173-47-6"> <oxides> <oxide symbol="CaO" name="Calcium Oxide, Calcia" status="" percent="0.350" tolerance=""/> <oxide symbol="Li2O" name="Lithium Oxide, Lithia" status="" percent="1.200" tolerance=""/> <oxide symbol="MgO" name="Magnesium Oxide, Magnesia" status="" percent="25.500" tolerance=""/> <oxide symbol="K2O" name="Potassium Oxide" status="" percent="0.150" tolerance=""/> <oxide symbol="Na2O" name="Sodium Oxide, Soda" status="" percent="3.000" tolerance=""/> <oxide symbol="Al2O3" name="Aluminum Oxide, Alumina" status="" percent="0.350" tolerance=""/> <oxide symbol="SiO2" name="Silicon Dioxide, Silica" status="" percent="53.750" tolerance=""/> </oxides> <volatiles> <volatile symbol="H2O" name="Water" percent="14.400" tolerance=""/> <volatile symbol="Cl" name="Chlorine Gas" percent="0.300" tolerance=""/> </volatiles> </material>


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