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a stable cone 10 black satin glaze

updated mon 5 jun 00


John Hesselberth on sat 3 jun 00

Anne Worner has again been developing and testing glazes. She has now
developed a very nice Black Satin Cone 10 oxidation glaze. It is very
stable with a good mix of fluxes and plenty of alumina and silica. Cobalt
leaching is less than 0.05 mg/l (the detectable limit). I'm posting it
with her permission. Anne has also supplied photos of the glaze on her
porcelain pots both with and without the cobalt (it is a black/brown
without the cobalt). You can see them on my site at:

Worner Black

Custer Feldspar 35.65
Whiting 6.09
Dolomite 10.43
Flint 28.70
EPK 19.13

RIO 10
Cobalt Carbonate 1.5

Thanks Anne! Does anyone else have any results to send to me??

John Hesselberth
Frog Pond Pottery
P.O. Box 88
Pocopson, PA 19366 USA
EMail: web site:

"Pots, like other forms of art, are human expressions: pleasure, pain or
indifference before them depends upon their natures, and their natures
are inevitably projections of the minds of their creators." Bernard
Leach, A Potter's Book.