iandol on wed 13 aug 03
Dear Zoe Paddy Johnson,=20
Yes, this is possible but you will not know what the composition is =
unless you have an analysis done. It may not be quartz!
One thing to remember is that beach sands often contain significant =
amounts of Aragonite, a form of crystalline Calcium Carbonate and source =
of Calcium oxide which comes from broken up sea shells. This can have =
significant effects on the behaviour of any mixtures you might prepare.
I recall long ago a colleague of mine who found a wonderful plastic =
white clay like material on a nearby beach. Blended in well with our =
stoneware to give a light body with wonderful throwing characteristics. =
Unfortunately test pots became pools of lava when fired to cone 8. The =
plastic beach clay had a significant amount of broken shell in it, =
washed finer than talcum powder.
As is often said, test, test, test.
Best regards,
Ivor Lewis. Redhill, South Australia
Zoe Paddy Johnson on thu 14 aug 03
This particular beachsand is largely quartz, with small grains of basalt,
plus minor amounts of shell. This per one of the my geologist kids who
looked at it under a binocular scope...
What is the effect of the shell?
ZoeJ
Paul Herman on thu 14 aug 03
Hi ZoeJ,
The effect of shell will be the same as Whiting (CaCO3), A flux.
Best wishes,
Paul Herman
Great Basin Pottery
423-725 Scott Road
Doyle, California 96109 US
potter@psln.com
> This particular beachsand is largely quartz, with small grains of basalt,
> plus minor amounts of shell. This per one of the my geologist kids who
> looked at it under a binocular scope...
>
> What is the effect of the shell?
> ZoeJ
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