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Date: | Thu, 11 Mar 2004 13:49:20 -0600 |
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What is Ball Clay?
Ball clay is an extremely rare mineral found in very few places around the
world. Its name dates back to the early methods of mining when specialized
hand tools were used to extract the clay in rough cube shapes of about 30
cm. As the corners were knocked through handling and storage these cubes
became rounded and ‘ball’ shaped. It also is sometimes referred to as
plastic clay.
For more details:
http://www.ima-na.org/about_industrial_minerals/ball_clay.asp
And....http://www.wbb.co.uk/web/website.nsf/0/a960b9cb0cff152d80256caf004c74c7?OpenDocument
What is the Difference between Ball Clay and China Clay?
The mineral kaolinite forms a major component in both ball clay and china
clay (which is also known as kaolin). But the two materials are quite
different from each other.
China clay (mostly composed of kaolinite, mica and quartz minerals)
remained in the place where it was formed as the feldspars in the granite
decomposed. In South West England, the funnel-shaped deposits of china clay
remain located amidst their parent rock - the surrounding "granite matrix".
However, ball clay is a sedimentary clay - carried far from where the
kaolinite was first formed. Rivers and streams washed away the decomposed
granite, mixing it with other clay minerals, sands, gravels and vegetation
as they flowed down from the uplands to form the deposits of ball clay in
low lying basins. In ball clays, there are usually three dominant minerals:
from 20 - 80% kaolinite; 10-25% mica, and 6-65% quartz. In addition, there
are other from 20 - 80% kaolinite; 10-25% mica, and 6-65% quartz. In
addition, there are other 'accessory' minerals and some carbonaceous
material (derived from ancient plants). The wide variation in minerals
make-up, and in the sizes of the clay particles result in different
characteristics for individual ball clay seams.
And yet even more info on Clay:
http://www.bsu.edu/web/jcflowers1/rlo/lceramicsclay.htm
Smoke
Smoke (Michael A.) Pfeiffer, RPA
Ozark-St. Francis National Forests
605 West Main Street
Russellville, Arkansas 72801
(479) 968-2354 Ext. 233
e-mail: [log in to unmask]
It is easier to get forgiveness than permission.
George Myers
<georgejmyersjr@h To: [log in to unmask]
otmail.com> cc:
Sent by: Subject: Fw: stem bore diameters
HISTORICAL
ARCHAEOLOGY
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03/11/2004 12:24
PM
Please respond to
HISTORICAL
ARCHAEOLOGY
----- Original Message -----
> The other problem is are pipes made from pipe-clay or kaolin? (terra
alba).
> Pipeclay is defined in WordWeb as "Fine white clay used in making tobacco
> pipes and pottery and in whitening leather" I have been told, correctly
not
> kaolin.
>
> George Myers
>
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