[Fwd: Cob: clay colors]

[Harry]

Charmaine R Taylor wrote:
> 
> > "ToSwink" <toswink at mindspring.com> said: IF you saw layers of color clay
> > like blue,yellow,white,red or
> > other colors
> > would you ask what minerals that this near? Sometimes color clay
> > suggest
> > others minerals in same area. I am clueless but would like to
> > know more.
> >
> > +++++++++++++
> >
> > I will do some research- I've got a couple great techy books to go
> > thru,  but basically all clay is a weathering og feldspar and
> > quartz..other impurities are PROBABLY what the color is from...but multi
> > colored clays are found world wide...I woould love to see purple myself,
> > but have seen red, white, rust, pinkkish, cinnamon blueish and more
> > "earth tones"
> >
> > I used a deep burgandy clay from Rough & ready ( love thatname) CA, and
> > my walls came out apricot gold when I used the clay in lime water to
> > make a natural paint... very thin amounts of clay made a pale orange on
> > a differnt wall surface.  so you can mix to get other colors it seems
> > form a few samples.

Hi!  Clays are colored by oxides of metals.  You can buy clay colors
from companies that sell clay supplies, like American Clay (I think
that's the name).  Red is iron oxide.  Some are very traditional colors
for paints, like yellow ochre.  Orange could be chrome oxide. White
could be zinc oxide, which is pretty expensive nowadays.    

Harry