[Clayart] no labor porcelain
hmurrow at efn.org
Wed Dec 30 09:47:58 EST 2015
On Dec 29, 2015, at 7:25 PM, Robert Harris via Clayart <clayart at lists.clayartworld.com> wrote:
> Just as an addendum to what you say Ric. As far as I know all U.S. Kaolins
> (or at least the commercially exploited ones) are secondary clays.
> Whereas several of the European Kaolins (e.g. those from Corwall, and
> France, used to make Grolleg and Limoges porcelains respectively), are
> primary clays and therefore do not have the extra titanium that prevents
> translucency in many domestic porcelains.
One more point from Eugene, OR;
Alaska has several deposits of sericitic volcanic ash which make beautiful white porcelains, closely resembling
the porcelains of Jingdezhen, which is not so surprising as they come from the same sort of geology. This geology(hydrothermally altered volcanic ash) is widely occurring along the Pacific 'rim of fire'. Some Chilean potter may read Clayart one day and later find 'petuntse' in his backyard!
So far, we have found several deposits in the Oregon Cascades, but most have enough iron/rutile brought in by subsequent out-gassing that they are not white, though beautiful(like the Longquan bodies) and ringing like a bell.
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