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cornwall stone/df

updated fri 29 oct 04

 

Gary Navarre on thu 28 oct 04


Hay Andrew,
Thanks for the input! I guess all I had to do now was go to the shed
and look at the bag. Waha, "DF Stone" right there on the old Rovin
label.

mailtoandrew@FSMAIL.NET
Wed, October 27, 2004 5:04 am wrote:


Hello Bonnie,

"For some years after only two grades were sold; both were similar blends
of Soft white and Hard purple. The difference between the two was one was
treated to remove a small amount of a fluorine bearing mineral whilst the
other was not. Sometime during the mid 1990s the treated grade, called DF
stone, was withdrawn. The other grade continues to be produced."

So I have a sack of the grade treated to remove fluoride?

"As you note the unfired colour is not white due to the presence of a
very small amount of stain, added during processing to differentiate
from other materials, without which it would be white."

This does not appear to have any stain and while not exactly clumpy my
finger leaves a print in a table spoon of the stuff.

"Rather than boring other ClayArters I hope you will not mind if I email
you further information."

Not at all boring for some of us, I find the history of antique
materials usefull for when they are found old farts like Bonnie or I
can know what it is and try to do that next thing we were going to try
before the well ran dry. Would you please send me some of that further
information too since I started this when Gawaine Dart clayed foreword
to me (still in this life) a big o'll sack of the stuff. For example,
would there be any advantage using it in making some porcelain or just
save for glaze and use other more common feldspars for a clay body.?

Thanks again, Andrew, ya helped big time, keep coming back, and stay in
there!

G. in Da U.P.
Navarre Pottery
Norway, Michigan, USA