Stephani Stephenson on fri 31 mar 06
I have been using Roseville clay as the basis for a slip I use
I remember Roseville pottery as having a yellow color and wanted
to see if the clay imparted that same lovely buttery color
I wanted a warmer yellow gold color in my clay body
Roseville is mined by Cedar Heights, who also brings us goldart and
redart.
I visited the the Cedar Heights booth at NCECA to ask about it. It is
from the same mine.
They showed me photos of the mine and areas where they extract the
different clays
which was quite interesting. But they couldn't tell me much more about
the handling properties, etc.
( though I did pick up some temporary "Roseville clay ' tatoos at the
booth, (not as useful , but nice!)
Right now I have to special order the Roseville through my Laguna
distributor ,
special order from Ohio ,
so it is a bit expensive for me to use in clay body
I do love the color it imparts as a slip.
I also wonder why it is not used or mentioned more
as it has some nice properties
with the loss of other commercially available clays, this stoneware
clay might be a great addition to the studio
I would like to explore it more as well.
If I was back east, where it is readily available I would certainly
check it out.
(hint, hint, Jon! I wish West Coast Laguna kept it in stock!)
Also I think maybe it must be just a certain combination of say, Iron,
Titanium, etc.
that imparts the color, could be had by using oxides with another clay
but I like the idea of using the clay as it is
the gold color starts showing up at cone 02 and can be made a deeper
shade of gold with addition of frit
haven't seen what it does above cone 2
Laguna catalog includes Roseville among with other clays in the Raw
Materials section
listed as follows
Al2O3 60.8 %
SiO2 23.4
Fe2O3 2.1
TiO2 1.7
MgO 0.2
CaO 0.4
Na2O 0.3
K2O 2.5
LOI 8.5
PCE Cone 23
with regard to the mulcoa
I have been using it , as well as Kyanite for grog.
I'll have to refer to the bags to refresh my memory as to the numbers
on the mesh size
best wishes
Stephani
Eleanora wrote:
Doing more early am noodling about clay bodies and came up with
Roseville clay,
mined in Ohio, "C1-8 stoneware clay fires gold color" and just wonder
why I have
never come across it in a recipe. Sounds very nice. Anybody
familiar with this clay?
Also talking to Arthur at Laguna Ohio about grogs. He mentioned
Mulcoa, which
sounds like it is related to mullite. Is it really a grog? Laguna
carries 48 and 200
mesh.
I am actually looking for a "60-80 mesh grog" called for in lots of
the recipes.
Missouri 70 mesh is the one Laguna carries.
As always, thanks in advance.
Eleanora
www.eleanoraeden.com
Stephani Stephenson
steph@revivaltileworks.com
http://www.revivaltileworks.com
steve baker on thu 6 apr 06
Dear Stephani,
Roseville is mined at Saltillo, Ohio (that is a clay sounding name, and there were some little potteries there), about 3 miles west of Roseville south of Zanesville, Ohio. Cedar Heights mines Goldart at Oak Hill, about 90 miles south of the Roseville pit. They do not come from the same mine, but are from the same company. Salt Lick Stoneware clay comes from the same mine as the Goldart, but a different layer.
I was always told it was the rutile (w/titania) that inparted golden colors to fired fireclays. Roseville also has a bit of a high iron content for a clay that birns so clean in reduction, vs. say a goldart. The first glazed reduction fired test we ever ran with Roseville gave practically no spots at all in the glaze, vs. the usual peppering of spots that is in even the best of Goldart, which rarely shows more that 1.5% iron. Most of the iron in Goldart is in the form of pyrite, which on decomposing goes rapidly to fayallite in the presence of silica, which is basically irony glass at that point. The iron in Roseville must be of a less reactive compound.
If you want to see Roseville clay at its absolute finest, study the pottery of the production pottery from that area called Watt Pottery. It is straight clay, simple fruit decorations like apples, and clear glaze. The really old stuff is a beautiful golden color. Also, nearly every single buff birdbath you have ever seen is at least 50% Roseville clay.
A sidenote- The true geological name of the Roseville Clay is Tionesta Clay, named after the small town in Pennsylvania where the accompanying coal seam is well developed. When the coal seam above the Roseville clay is well developed and minable in Ohio(which doesn't happen often), it is the lowest sulfur coal seam to be found, with sulfurs below 1%.
steve
Stephani Stephenson wrote: I have been using Roseville clay as the basis for a slip I use
I remember Roseville pottery as having a yellow color and wanted
to see if the clay imparted that same lovely buttery color
I wanted a warmer yellow gold color in my clay body
Roseville is mined by Cedar Heights, who also brings us goldart and
redart.
I visited the the Cedar Heights booth at NCECA to ask about it. It is
from the same mine.
They showed me photos of the mine and areas where they extract the
different clays
which was quite interesting. But they couldn't tell me much more about
the handling properties, etc.
( though I did pick up some temporary "Roseville clay ' tatoos at the
booth, (not as useful , but nice!)
Right now I have to special order the Roseville through my Laguna
distributor ,
special order from Ohio ,
so it is a bit expensive for me to use in clay body
I do love the color it imparts as a slip.
I also wonder why it is not used or mentioned more
as it has some nice properties
with the loss of other commercially available clays, this stoneware
clay might be a great addition to the studio
I would like to explore it more as well.
If I was back east, where it is readily available I would certainly
check it out.
(hint, hint, Jon! I wish West Coast Laguna kept it in stock!)
Also I think maybe it must be just a certain combination of say, Iron,
Titanium, etc.
that imparts the color, could be had by using oxides with another clay
but I like the idea of using the clay as it is
the gold color starts showing up at cone 02 and can be made a deeper
shade of gold with addition of frit
haven't seen what it does above cone 2
Laguna catalog includes Roseville among with other clays in the Raw
Materials section
listed as follows
Al2O3 60.8 %
SiO2 23.4
Fe2O3 2.1
TiO2 1.7
MgO 0.2
CaO 0.4
Na2O 0.3
K2O 2.5
LOI 8.5
PCE Cone 23
with regard to the mulcoa
I have been using it , as well as Kyanite for grog.
I'll have to refer to the bags to refresh my memory as to the numbers
on the mesh size
best wishes
Stephani
Eleanora wrote:
Doing more early am noodling about clay bodies and came up with
Roseville clay,
mined in Ohio, "C1-8 stoneware clay fires gold color" and just wonder
why I have
never come across it in a recipe. Sounds very nice. Anybody
familiar with this clay?
Also talking to Arthur at Laguna Ohio about grogs. He mentioned
Mulcoa, which
sounds like it is related to mullite. Is it really a grog? Laguna
carries 48 and 200
mesh.
I am actually looking for a "60-80 mesh grog" called for in lots of
the recipes.
Missouri 70 mesh is the one Laguna carries.
As always, thanks in advance.
Eleanora
www.eleanoraeden.com
Stephani Stephenson
steph@revivaltileworks.com
http://www.revivaltileworks.com
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