Craig Martell on tue 24 nov 98
Hi:
My spodumene preference for shinos, or any other glaze that requires
spodumene, is Ceramic Grade. I use the old Foote Minerals stuff that hasn't
been available for a long time. Chemical Grade Spodumene is lower in
lithium and higher in iron. You can adjust the receipe to get the correct
amount of lithium but the iron in this stuff is harder to deal with.
Ceramic Grade Spod fires out to a real dirty brown fusion at cone 10 R. I've
done fusion buttons of the stuff and seen this. The quantitative analysis
of Chemical Grade says that it has 2% iron but it has to be a lot more than
that according to what I've "seen" in the fired fusions. It looks to be
upwards of 5% or so.
regards, Craig Martell in Oregon
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