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mica (minerals?)

updated sat 30 may 98

 

Gabrielle M. Madsen on mon 25 may 98

Hello Again Fellow Rakuers!

Can someone please explain what "Mica" is in reference to the
potters useage & where it is available at?

Thanks Again in Advance!
Gabrielle M. Madsen
pearcelr@island.net

Cindy on fri 29 may 98

Gabrielle,

Mica "grows" in pretty layered sheets of silvery stuff in quartz veins.
They get a lot of it when mining feldspar, too. It has been used for
windows in high temperature furnaces, but all in all, there's not a real
big commercial market for it. I have some powdered mica which looks like
high-class glitter. I put it in a kitchen shaker and sprinkle it on an
occasional piece (things destined for the firing pit.

I haven't gotten around to trying it as a glaze ingredient, but here's the
formulation according to the people who gave me the mica.

K20 0.913
Na2O 0.087
Al2O3 3.144
SiO2 9.178
Fe2O3 0.015

It loses its sheen somewhere below ^6, but it's lovely on pit-fired pieces.
I don't do raku as of yet, so I can't help you there. You may be able to
get it from Pacer Corp. (the folks who bring you Custer spar) Their phone
number is: (605)673-4419.

Cindy Strnad
Earthen Vessels
Custer, SD
USA http://blackhills-info.com/a/cindys/menu.htm