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granite

updated mon 9 may 05

 

ASHPOTS@aol.com on fri 7 jun 96

HOWDY ALL: ARE ANY OF YOU FROM KENNESAW, GEORGIA USA? The home of the
"General"? I need to get ten gallons of dry granite dust. It is great in
glaze.

Capt. Mark Issenberg
MADE IN THE SHADE PLANTS & POTTERY
7780 SW 118th Street
Miami, FL 33156
(305) 232-0278
(305) 232-0278 FAX

June Perry on fri 7 jun 96

Dear Mark:

You can either come visit me here in Southern Oregon and get your granite
dust or you can check out the Yellow Pages for your local garden
centers and/or rock and stone dealers.
You can also check out some maps of your area. Our local Bureau of Land
Management office has maps of the state showing clay and other deposits.

Good luck!
June Perry
EMail: Gurushakti@aol.com

Tim Lynch on fri 7 jun 96

Have you tried your local tombstone carverr? Ours has tons of the stuff
for free.

T. Lynch

On Fri, 7 Jun 1996 ASHPOTS@aol.com wrote:

> ----------------------------Original message----------------------------
> HOWDY ALL: ARE ANY OF YOU FROM KENNESAW, GEORGIA USA? The home of the
> "General"? I need to get ten gallons of dry granite dust. It is great in
> glaze.
>
> Capt. Mark Issenberg
> MADE IN THE SHADE PLANTS & POTTERY
> 7780 SW 118th Street
> Miami, FL 33156
> (305) 232-0278
> (305) 232-0278 FAX
>

jason barnes on sat 8 jun 96

If you are willing to share your granite glaze recipe I would like to know it. I
am currently testing several glazes using local granite as part of my studies
and another recipe to test would be great.

TIA.

Jason Barnes
3rd Year B.A.(Ceramics)
LaTrobe University, Bendigo
Victoria, Australia.

ASHPOTS@aol.com on mon 10 jun 96

Howdy All: I have been using ash glazes at Cone 6 and Cone 10. I have been
trying to keep them simple, using just red clay and ash, 50-50. I did a show
in North GA. in Rising Fawn and a friend brought me granite dust. I came
home, did a firing-Cone 10, using granite dust and ash, 50-50. It was
fantastic. The ash I have is from trees that were knocked down during
hurricane Andrew and I have some friends who own a sawmill. Most of the wood
they cut was mahogany but there were other exotics as well and that's what
I've been using for ash. If anybody else is working on ash glazes, let's
share. Also, if anybody is going to make a video of the Village of Onda, I
want a copy, too. Charles Counts had it at a workshop that I took from him
and 1968. Somebody ask Charles if he still has a copy. What a great film.

Mark

Dave Hedblom on fri 14 jun 96

50-50 ash and granite. Is that by weight or volume?


Dave Hedblom
cobalt@winternet.com



At 08:43 AM 6/10/96 EDT, you wrote:
>----------------------------Original message----------------------------
>Howdy All: I have been using ash glazes at Cone 6 and Cone 10. I have been
>trying to keep them simple, using just red clay and ash, 50-50. I did a show
>in North GA. in Rising Fawn and a friend brought me granite dust. I came
>home, did a firing-Cone 10, using granite dust and ash, 50-50. It was
>fantastic. The ash I have is from trees that were knocked down during
>hurricane Andrew and I have some friends who own a sawmill. Most of the wood
>they cut was mahogany but there were other exotics as well and that's what
>I've been using for ash. If anybody else is working on ash glazes, let's
>share. Also, if anybody is going to make a video of the Village of Onda, I
>want a copy, too. Charles Counts had it at a workshop that I took from him
>and 1968. Somebody ask Charles if he still has a copy. What a great film.
>
>Mark
>
>

John Baymore on tue 18 jun 96

----------------------------Original message----------------------------
From: Dave Hedblom
Subject: Re: GRANITE

50-50 ash and granite. Is that by weight or volume?
-------------------------------------------------------------------
Dave,

From my experience, that is probably by weight.

I have been working with local raw materials for many years here in NH (the
GRANITE STATE ). Try a triaxial with granite, ash, and local red clay on
the three axies. You'll have enough ideas to keep you going a lifetime!

........................john

John Baymore
River Bend Pottery
Wilton, NH

76506.3102@Compuserve.com
http://www.CraftWEB.com/org/jbaymore

ROGER BOURLAND on wed 19 jun 96


I'm intrigued with the granite ideas. I can't find a source in either
clay or horticultural catalogues for granite dust. Can anyone make a
suggestion?

Roger Bourland

dannon@ns1.koyote.com on thu 20 jun 96

>----------------------------Original message----------------------------
>
>I'm intrigued with the granite ideas. I can't find a source in either
>clay or horticultural catalogues for granite dust. Can anyone make a
>suggestion?
>
>Roger Bourland
>
>
I believe this has already been suggested, but a good source for granite
dust is your local grave marker - maker. Most gravestones are granite; the
dust is often blown out of the workroom to some other location, where it
lies in greater or lesser piles.
Sometimes it will have a soupcon of marble or other dusts in it....

June Perry on thu 20 jun 96

Oftentime largee garden centers which sell bulk dirt and gravel will also
sell decomposed granite. If not, you may try your local headstone
manufacturers. They would have some.
I don't know where you live but you may want to check out your local bureau
of land management office and talk to the resident geologist. They can often
point you in the right direction if you have some natural deposits in your
area. In southern Oregon, where I live, we have plenty of decomposed granite
readily available.

Good luck!
June Perry
Email: Gurushakti@aol.com

Dave Hedblom on thu 20 jun 96

I called a local monument company. I promised the owner I would show him a
sample of the end product.

cobalt@winternet.com
Dave Hedblom in Minnesota

At 05:30 PM 6/19/96 EDT, you wrote:
>----------------------------Original message----------------------------
>
>I'm intrigued with the granite ideas. I can't find a source in either
>clay or horticultural catalogues for granite dust. Can anyone make a
>suggestion?
>
>Roger Bourland
>
>

Eric Lindgren on fri 21 jun 96

>----------------------------Original message----------------------------
>
>I'm intrigued with the granite ideas. I can't find a source in either
>clay or horticultural catalogues for granite dust. Can anyone make a
>suggestion?
>
>Roger Bourland


Dear Roger,

I got mine for free at a friend's new drilled well. You might contact a
well-driller... It was coarse material, with some fine particles. Minimal
ball-milling was needed.

Eric Lindgren
lindgren@muskoka.com

____________________

MarilynMFA@aol.com on fri 21 jun 96

It has been interesting to see the replies to the question by Roger Bourland
about his need for a source for granite dust. Four or five people have
suggested that he try the grave marker-makers or monument makers. Two or
three years ago, I tried to tap this same resource (among others) but found
that the grave stones are sand-blasted with some type of black sand that
intermixes with the granite dust making it almost impossible to salvage any
appreciable amount of pure or even nearly pure granite dust. For tests
(don't laugh please), I even took a hammer and tried to crush a piece of
granite. It took nearly three hours to crush and sieve enough for a 100 gram
test. Needless to say, I eventually abandoned the thought of even using
granite dust.

There is a superb book by Joseph Grebanier called "Chinese Stoneware Glazes",
published in 1975. It seems like every other glaze recipe that he specifies
requires this obdurate ingredient. [[They are beautiful glazes!]] I would
happily pay the shipping costs if there were some ceramic supplier that would
stock this raw material! Are you listening Axner? Bennett's? Kickwheel?
Laguna? Minnesota? Bailey? Georgie's? Aardvark? Continental? et.al.?

Marilyn, in Utah

Richard Gralnik on sat 22 jun 96

My neighbor works for Battaglia a company that shapes granite
and marble counter tops and other things. I went by the factory one
afternoon thinking I'd stumbled onto glaze raw material heaven.
Unfortunately, the process they use, which goes back to Roman days,
involves working on a large (20' square) slab, with water running over
the stone to cool it and wash away the dust. The dust goes into a
channel on the side of the slab, down a chute into a large sump
tank. Unfortunately they also do marble work on the same slabs
so the sump tank is a mix of all kinds of granite and marble.
Oh well.

I also learned that all granite is not created equal. They have
slabs from all over the world, in colors from white to pink to
gray to black and mixtures of all four. My neighbor gave me some
small chunks of various granites to try as glaze test materials, but
I don't happen to have a pulverizer in my garage.

Someone here posted a note once that calcining the raw stone makes
it very brittle and easy to break up. I haven't had a chance to
try that yet, but I'll report here when I do. If someone else has
a chance to test it first please let us all know how it works out.

Richard

Leonard Smith on thu 27 jun 96

I haven't followed this thread carefully and I may be repeating things
already said. So here goes, please forgive me if it's been said before.

Locally we have a plant that cuts granite, and marble for bench tops etc.
In the process they have a flow of water over the blades to cool them and
all this runs off to a holding trough to keep it out of the drains. This
sludge is a wonderful source of a very fine grade of glaze material. I have
only just collected a quantity of the mixture, enough to be worthwhile
testing (ie about 40 kg). It is of course a mix of granites (light and
dark) and marble (CaCo3). I have yet to do some tests but they are comming
once I have dried the sludge out and mixed it well.

When collecting granite in the wild the first process is to calcine it in a
bisue kiln. I usally place it in an old bisqued pot and place it in the
coolest spot. Once calcined it can be broken up quite easily and broken
down to a smaller size with mortar and pessel. You can either grind it all
down or hand sort the feldspar etc out. Either way you then need to ball
mill it to a size usable in glazes.



Best wishes

---------------------------------------------------------------------------
Leonard Smith ARCADIA STUDIOS Email: smithl@ozemail.com.au

10 Marrakesh Place
Arcadia, 2159, NSW, Australia. Phone + 61 2 653 2507
^^^^^^^^^^^^^^^^^^^^^^^^
SEE OUR NEW WEBB SITE AT
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
http://www.ozemail.com.au/~smithl/
---------------------------------------------------------------------------

Susan Maguire on sat 29 jun 96

I wish while you were asking all these companys about the granite
you would have asked for some Buckingham spar as well.. The
'Grebanier' glazes just arn't quite the same since I ran out!



Susan Maguire, Fort Lauderdale, Florida

smaguire@bcfreenet.seflin.lib.fl.us

On Fri, 21 Jun 1996 MarilynMFA@aol.com wrote:

> ----------------------------Original message----------------------------
> It has been interesting to see the replies to the question by Roger Bourland
> about his need for a source for granite dust. Four or five people have
> suggested that he try the grave marker-makers or monument makers. Two or
> three years ago, I tried to tap this same resource (among others) but found
> that the grave stones are sand-blasted with some type of black sand that
> intermixes with the granite dust making it almost impossible to salvage any
> appreciable amount of pure or even nearly pure granite dust. For tests
> (don't laugh please), I even took a hammer and tried to crush a piece of
> granite. It took nearly three hours to crush and sieve enough for a 100 gram
> test. Needless to say, I eventually abandoned the thought of even using
> granite dust.
>
> There is a superb book by Joseph Grebanier called "Chinese Stoneware Glazes",
> published in 1975. It seems like every other glaze recipe that he specifies
> requires this obdurate ingredient. [[They are beautiful glazes!]] I would
> happily pay the shipping costs if there were some ceramic supplier that would
> stock this raw material! Are you listening Axner? Bennett's? Kickwheel?
> Laguna? Minnesota? Bailey? Georgie's? Aardvark? Continental? et.al.?
>
> Marilyn, in Utah
>

JeffreyAsm on wed 10 jul 96

One possible way to create your own granite dust would be to grind a piece
of the granite with a 4"disc grinder(Makita brand -$60) mounted with a
diamond blade($40). You can get granite 'scraps' and diamond blades from
ceramic tile distributors and a Makita disc grinder from Home Depot. The
diamond blade cuts granite,marble,tile,flagstone etc. ...comes in handy.
This method will create a fine powder if that's what your looking for.
--Tile Contractor--

John Baymore on sat 13 jul 96

From: JeffreyAsm
Subject: Re: Granite

----------------------------Original---------------------------
One possible way to create your own granite dust would be to grind a piece
of the granite with a 4"disc grinder(Makita brand -$60) mounted with a
diamond blade($40). ...................
------------------------------

It would take a lot of grinding to make enough dust to be useful, IMHO. The
first 50 lb bag's worth would cost $100, exclusive of labor to produce it (just
for the tools). That labor would make the price of a 50 lb bag of the stuff
work out to a couple thousand dollars I'd bet .

Most landscaping firms (at least in the east) sell what they call "granite
dust". Pretty cheap stuff. This "dust" is really a mixture of about grain of
rice size down to fines. More like dusty sand . If you simply seive it very
wet through a 200 mesh screen, you'll get about 20% to work with in glazes.
Fun, but not very practical..... lots of work for little return. (Been there,
done that, got the T shirt)

However, if you put this "granite dust" from the landscape supplier in a ball
mill and mill for about 4-5 hours at about 70% of critical speed, you'll get
about 99.9% useable material. That is what I now do, although I get my "dust"
from a local quarry here in town. I also get the typical analysis for the
material from them...... architects need that information for weathering and
strength info.

BTW, the granite dust you get can contain more than granite. If it is coming
from a quarry and not a granite "finisher" (counter tops, etc.), some of them
still use wire saws that cut the granite with a silicon carbide powder. From
that it'll pick up iron oxide (rust from the wire) and silica (from the silicon
carbide). Also, many granite outcroppings occur under or sandwiched between
layers of other types of rocks.

(Interestingly, modern quarrys are now using a high pressure stream of WATER to
cut the stone!!!!! I have watched it in operation...... it is amazing. It is
accelerated, localized, weathering of the rock.)

If you are mixing glazes containing the granite, you can save yourself a big
step by mixing the unmilled material into the glaze, and then ball milling the
whole batch. The amount of granite that doesn't mill to a fine enough size is
negligible, so you save drying it out to weigh it. Plus the milling of the
entire glaze will make it nicer in general.

Home-processed granite settles terribly in glazes, because the particle size is
actually pretty coarse compared to the commercial materials we are used to.
Welcome to the world of the primitive folk potter . Your glaze will need
some clay to help keep things up in the liquid. Bentonite or Macaloid is a good
addition too.

.......................................john

John Baymore
River Bend Pottery
Wilton, NH

"The Granite State"

76506.3102@Compuserve.com

http://www.CraftWEB.com/org/jbaymore/rivrbend.shtml


PS: If there is enough interest, I may package up the local NH quarry "dust"
(not milled) and become a "Ceramic Raw Materials Supplier" . Contact me off
the list if you are interested.

Barbara Webb on tue 16 jul 96

I have checked into this granite dust thing. In Kennesaw, GA there is a
place that sells it. It costs $18.95 for a dumptruck load of what they
call "granite powder". You bring your own dumptruck. When I asked about
smaller quantities they told me that there is a $10 minimum and I could
bring a pickup truck to fill up for $10. I looked at this stuff and it
is slightly coarser than baby powder. This place I talked to was Vulcan
Materials Company-- Southeast Division, 1272 Duncan Rd. NW, Kennesaw, GA
30144, (770)427-2401. I don't know anything about this company and I
have never made any of this type of glaze so I am not sure if this stuf
is the right texture.
Barbara Webb
barbara@fujikura.com
Marietta, Ga
"Hiding up here until the Olympics is over"

GURUSHAKTI on wed 7 jan 98

Try using the granite as a sub for feldspar. The composition of granite
varies, so test. Somewhere in my notes I have some granite formulas. If I can
dig them up I'll post them.

Regards,
June

Linda M on mon 10 may 04


Has anyone put small pieces of granite on a clay piece and then fired it?
In the archives all I've been able to find on granite is making granite
dust to put in glaze. I have a large piece of granite that I thought I'd
break up into small pieces and see what kind of decoration it would make
after being fired. I know that glass melts. Wonder what granite would do.
Any input on this would be greatly appreciated.

Al Sather on mon 10 may 04


Hi Linda

I have used Chick Grit kneaded into clay, and
fired to ^6. I used the "starter grit" as it is
the finest.
I played with it a bit, but I did not like the
tearing of the clay I got as I was throwing it.
I ran out of time to play with it further. I got
the idea from another potter, who I believed
fired to ^10 (treat that as hearsay, because I
just do not remember).

I see no reason why it could not be put into a
glaze. It will settle right out of the glaze
slurry, I would expect. It is like little rocks.
And, I do not think it would become part of the
melt. Could be wrong, though. Try it and see
what happens.

I looked granite up on Tony Hansen's site
http://digitalfire.ab.ca/cermat/material/1888.ht
ml
and found little or no information.

One word of caution. When you are at the feed
store, make sure it is Granite you are buying
and not Oyster Shell. Both will work in the
crop of a chick, but oyster shell is essentially
whiting (CaCO3).

Al Sather
Dogberry Clay Studio
Maple Ridge BC

-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG]
On Behalf Of Linda M
Sent: Monday, May 10, 2004 5:20 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: [CLAYART] Granite

Has anyone put small pieces of granite on a clay
piece and then fired it?
In the archives all I've been able to find on
granite is making granite
dust to put in glaze. I have a large piece of
granite that I thought I'd
break up into small pieces and see what kind of
decoration it would make
after being fired. I know that glass melts.
Wonder what granite would do.
Any input on this would be greatly appreciated.

________________________________________________
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Gary Navarre on tue 11 may 04


> "Has anyone put small pieces of granite on a clay piece and then fired it?
> In the archives all I've been able to find on granite is making granite
> dust to put in glaze. I have a large piece of granite that I thought I'd
> break up into small pieces and see what kind of decoration it would make
> after being fired. I know that glass melts. Wonder what granite would do.
> Any input on this would be greatly appreciated."
> Asked Linda M.

Linda,G. in da U.P.,
Michael Cardew discusses obtaining/processing feldspars in "Pioneer
Pottery" p.48. I'm planning on experimenting with rocks found around
Norway, Michigan probably sintering them in a second chamber off the
main chamber of the wood kiln I'm rebuilding. I could build a seperate
beehive sort of kiln out of red brick just for "loosening up" rocks and
not melt the brick, haven't made up my mind. A small kiln like that
could spell as a raku kiln too.
Must have got a dozen ticks on me working in the woods today.
Gary Navarre
Navarre Pottery
Norway, Michigan

Avril Farley on tue 11 may 04


Have a look at Nic Collins work on

http://www.studiopottery.com/potters/collinsnic.html

he throws very large pots adding quite large chunks of pebble and rock =
as he goes, and blast drying with a gas torch before firing in his =
anagama kiln- very hard on the hands, but then Nic is a very manly man!

Avril in the Forest of Dean, UK

John Baymore on tue 11 may 04


Linda,


Has anyone put small pieces of granite on a clay piece and then fired it?=



I don;t put the granite "ON" the pieces.... I put it IN the pieces. This=

is something I do all the time. New Hampshire is the "Granite State"....=
..
(Don't take us for Granite. ) so as a "personalization to location" I
use granite in many pieces of my work. It is used both in glazes and in
clay bodies. In glazes, I ball mill it for 6 hours......and all passes a=

120 m screen. In the clay bodies the granite I use runs from true "dust"=

up to about 1/4 inch chunks. The amount I use varies depending on the
effects I am trying to accomplish.

When I have been working making pots in Japan.... I have shipped some NH
granite dust over so that I can symbolically "merge" the two locations ju=
st
a bit. "East meets West" in a quite literal sense .

Granite's composition varies depending on the source. So what exactly it=

will do can vary a bit. But basically it melts somewhat. It can produce=

sort of like what the Japanese call "ishihaze".... stone stars. They oft=
en
burst through the surface of the clay and leave little bulges/lumps of
colored materials fused to varying degrees...... sort of like iron spotti=
ng
in reduction but totally different. It can take a "blah" glaze surface a=
nd
give it real "zing".
Some granite will not fuse all that much and stays more "stonelike" and=

some fuses to an almost complete fluid melt. When there is a glaze over=

it...... =

that changes to nature of the effect.

You can also try using "turkey grit" or "poultry grit". You can find it =
at
places like Agway. Those are bags of small "rocks" that birds use to
"chew" their food. The rocks in their gullet mash up the food. =

(Trivia.... many dinoasurs did the same.)
Turkey grit is large.... about 1/4 inch chunks. I have used turkey gri=
t
wedged into clay when I have presented workshops and couldn't get local
granite or some other good "rock" to add.
Sometimes I will wedge in so much granite dist and chunks that there i=
s
just enough clay to "stick it together". Nasty stuff...... I love it =
!

Try it ... you'll like it.


best,

.......................john


John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086-5812 USA

JBaymore@compuserve.com
http://www.JohnBaymore.com

603-654-2752 (studio)
800-900-1110 (studio)


"Earth, Water, and Fire Noborigama Woodfiring Workshop: August 20-29,
2004"

Tig Dupre on tue 11 may 04


---------------------------<>-----------------------------------
Has anyone put small pieces of granite on a clay piece and then fired it?
---------------------------<>-----------------------------------

Linda,

I have wedged a handful of crushed granite "chicken grit" into clay to make what I call "faux Shigaraki" clay. It's murder on the fingers to throw, so I throw VERY slowly.

When fired, it sometimes pops out of the surface, other bits burn black and brown, and some flux out in a puddle. Granite is the "sun source" of many pottery materials. At certain stages of decomposition, granite provides feldspars, silicaceous earth, and the fine particles of clay we use.

The "Starter Grit" is the finest grind commercially available, and doesn't cost much. Get it at your local feed store for a few bucks per bag. WARNING! One bag will last you a LO-O-O-ONG time!

I also buy crushed Custer feldspar at my suppliers and mix it in the clay. It burns somewhat like granite, but without the black spits and spots.

Good luck,

Tig Dupre
in Port Orchard, Washington, USA

Karen Sullivan on tue 11 may 04


I wander into the mountains in search of granite slides
that I collect and use in my clay.....
I collect various buckets...on a trip...
If I like the bucket of granite I have collected
it is very difficult to identify the location I managed
to gather...so I want enough from one trip...I then bring
them back and make a small pinch pot...drop a piece in and fire
it to see how it melts...
Try a piece to see the result...
Generally granite is feldspatic...and the size of the
particle determines it's melt in the clay...so it
stays a whole mass...looks like a melting...oozing bead
in the stoneware....
you can also use construction sand...smaller particles...
You get frosty...white beads...
So the surface begins to look like bizen clay...where
the feldspar is naturally occurring in the clay.

I tend to let the clay fire without a glaze...
so the raw clay becomes alive with the additions...
wood fired...or charcoal fired...look in the archives
for my descriptions of charcoal firing....

I have seen the granite used in glazes...
nubbly surface...
good luck

bamboo karen

Joseph Herbert on wed 12 may 04


Hurrah for John! Another Local Glaze!

The combination of New Hampshire Granite (the Old Stone Face symbol of the
state recently became available for use), ash from the White Birch (or
Lilac), and a selected till (the state dirt) should give us that "Glaze Free
or Die" combination of easily available (cheap) local ingredients.

On the subject of Turkey Grit: the rock that is used in poultry grit is
determined by availability and shipping costs. Often the grit is limestone
sometimes oyster shell, not really hard rock but easily processed. This
same kind of observation can be made for landscape gravel in different parts
of the country. If you intend to use some sort of rock you have purchased
at the farm center, home center, or landscape store, you might be less
surprised by the results you get if you determine the nature of the rock
they are selling. I would also mention that I have noticed cases where the
identification of the material on the package was wrong. Testing, as
always, is in order.

There was a federally funded study of using high hardness gizzard stones in
turkey husbandry. The idea was that feeding the turkeys topaz or corundum
fragments might lessen the cost burden on the turkey raising operations for
constantly supplying stones that wore away rapidly. There were never any
results published because the turkeys were off to slaughter before any
definitive results could be obtained. Seems that the one year life of the
turkey was insufficient to make any sort of meaningful impact on the high
hardness gizzard stones. Because of these problems, the study was
terminated after only 7 years (seven turkey cycles). Coincidently, the
length of the study matched the availability of funding exactly. (There
must be one of the smiley face things for tongue-in-cheek) ;-)

Joseph Herbert

kruzewski on wed 12 may 04


I would say the best way to find out is to make small test pots and try it,
maybe adding different sizes of rock and in different ways - ie in the clay,
on top of the glaze, whatever ways you can think of.

I tried this with some black basalt from Staffa (off the Mull, West Coast of
Scotland, the Isle made famous by "Fingalls Cave" music). No, I didn't go
there and chip bits off, some had fallen and smashed to pieces on the path
to the cave.

I wanted to make bowls containing a little bit of Staffa for my friends who
had been to Mull on a previous trip when we weren't able to make it to the
Island. I put a small rock into the centre of each bowl after I'd glazed it.
I had no real idea what would happen but as Hamer and Hamer said Basalt
would melt at 1250 centegrade - the temperature I fire at - I thought it
was worth a try. It worked well. I had a little "island" of melted, dark
brown to black slightly glittery on the edges in each bowl.

It's worth a try.

Jacqui

North Wales
----- Original Message -----
From: "Linda M"
To:
Sent: Tuesday, May 11, 2004 1:19 AM
Subject: Granite


> Has anyone put small pieces of granite on a clay piece and then fired it?

John Baymore on thu 13 may 04


Joseph,


The combination of New Hampshire Granite (the Old Stone Face symbol of th=
e
state recently became available for use), ash from the White Birch (or
Lilac), and a selected till (the state dirt) should give us that "Glaze
Free
or Die" combination of easily available (cheap) local ingredients.


So I was only trying to take a LITTLE piece of granite off him when he
collapsed ......... . It seemed like a great marketing idea.... "Old
Man of the Mountain Mugs". I would'a made a killing
in the tourist spots .


In fact I do use wood ash (mainly maple), a local glacial clay, and grani=
te
dust from the locality here to make a couple of glazes. One is the class=
ic
1/3 - 1/3 - 1/3 combination. Another local glaze I have uses ball milled=

river sand from my property, clay from 1/2 mile down the river, and wood
ash.



On the subject of Turkey Grit: the rock that is used in poultry grit is
determined by availability and shipping costs.


As Joseph has said... test, test, test.


best,

.......................john


John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086-5812 USA

JBaymore@compuserve.com
http://www.JohnBaymore.com

603-654-2752 (studio)
800-900-1110 (studio)


"Earth, Water, and Fire Noborigama Woodfiring Workshop: August 20-29,
2004"

Fred Hagen on thu 13 may 04


Please excuse a newcomers questions but what sort of glaze is created by the 1/3,1/3,1/3 of ash, clay, and granite dust. I have a source for granite dust here in Michigan but this is the first formula using it that I've seen. Does anyone have any other formula --say without the wood ash that uses granite --would the granite provide the silica ( I assume) for the glaze?
Also, I have a lot of St Helen's ash that I picked up last summer --anyone know how that could be used. I sent an email to Phil Rogers (UK) an authority and he said to try it in place of the feldspar --what other thoughts are out there?
Thanks Fred Hagen

John Baymore wrote:
Joseph,


The combination of New Hampshire Granite (the Old Stone Face symbol of the
state recently became available for use), ash from the White Birch (or
Lilac), and a selected till (the state dirt) should give us that "Glaze
Free
or Die" combination of easily available (cheap) local ingredients.


So I was only trying to take a LITTLE piece of granite off him when he
collapsed ......... . It seemed like a great marketing idea.... "Old
Man of the Mountain Mugs". I would'a made a killing
in the tourist spots .


In fact I do use wood ash (mainly maple), a local glacial clay, and granite
dust from the locality here to make a couple of glazes. One is the classic
1/3 - 1/3 - 1/3 combination. Another local glaze I have uses ball milled
river sand from my property, clay from 1/2 mile down the river, and wood
ash.



On the subject of Turkey Grit: the rock that is used in poultry grit is
determined by availability and shipping costs.


As Joseph has said... test, test, test.


best,

.......................john


John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086-5812 USA

JBaymore@compuserve.com
http://www.JohnBaymore.com

603-654-2752 (studio)
800-900-1110 (studio)


"Earth, Water, and Fire Noborigama Woodfiring Workshop: August 20-29,
2004"

______________________________________________________________________________
Send postings to clayart@lsv.ceramics.org

You may look at the archives for the list or change your subscription
settings from http://www.ceramics.org/clayart/

Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.

Paul Herman on thu 13 may 04


Hi Fred,

The only way to find out is to test it. Granite varies in composition,
but does have a lot of silica in it. Try various blends with your
volcanic ash, and clays. If it doesn't melt enough, flux it with
something.

I recently ground some granite to powder, but haven't fired it yet. This
stuff was decomposing, quite crumbly, the little jaw crusher ate it
right up, then it got ball milled for 6 hours to powder.

There's a good supply behind my place, above the railroad tracks. (The
Sierra Nevada)

good grinding,k

Paul Herman
Great Basin Pottery
Doyle, California US
http://www.greatbasinpottery.com/

----------
>From: Fred Hagen
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: Re: Granite
>Date: Thu, May 13, 2004, 12:58 PM
>

> Please excuse a newcomers questions but what sort of glaze is created by
> the 1/3,1/3,1/3 of ash, clay, and granite dust. I have a source for granite
> dust here in Michigan but this is the first formula using it that I've
> seen. Does anyone have any other formula --say without the wood ash that
> uses granite --would the granite provide the silica ( I assume) for the glaze?
> Also, I have a lot of St Helen's ash that I picked up last summer --anyone
> know how that could be used. I sent an email to Phil Rogers (UK) an
> authority and he said to try it in place of the feldspar --what other
> thoughts are out there?
> Thanks Fred Hagen

Louis Katz on sat 7 may 05


Depends. What temperature? What particle size? How big are the
individual crystals in the granite? How much Iron, What kind of
Granite.
Conclusion:
Try it.
Try it with some ash, some whiting, some frit try it with anything that
normally helps feldspar to melt at your temperature.
Wedge it in your clay.
Watch out for limestone if you wedge it in. My favorite deposit of
decomposed granite in Helena MT has some contamination from near by
limestone.
Mix some into a shino. Mix some into any old glaze. Let me know.
My experience is that by itself "granite chicken grit" tends to get
soft at cone 10 but finer ground stuff melts much earlier.

Louis

On May 7, 2005, at 4:07 PM, Linda Ferzoco wrote:

> Hi All,
>
> There's a kind of granite near me here in the San Francisco Bay area
> which
> is very crumbly from having moved about 300 miles north from the LA
> basin
> over the last kajillion years (the most extreme example of it is seen
> at the
> aptly named Devils Slide just south of where I live). It intrigues me
> as a
> potential glaze component. I can get quite sandy material, although I
> don't
> know the particle size distribution.
>
> This material is quite orangey/brown. I'm making the assumption that
> the
> color comes from iron content and hoping for some nice effects.
>
> What can I expect the melting point to be?
>
> Cheers, Linda
>
> _______________________________________________________________________
> _______
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots@pclink.com.
>

Rod Wuetherick on sat 7 may 05


> What can I expect the melting point to be?

Linda,

One of the easiest ways to work with rock glazes is to simply take your rock
put it into a bowl and bisque it as you would normally do with your other
work. Then you should ball mill and run simple blends with wollastonite. You
will find a working glaze very quickly.

I have alot of respect for people who make rock glazes they have so much
patience!

good luck,
rod

Linda Ferzoco on sat 7 may 05


Hi All,

There's a kind of granite near me here in the San Francisco Bay area which
is very crumbly from having moved about 300 miles north from the LA basin
over the last kajillion years (the most extreme example of it is seen at the
aptly named Devils Slide just south of where I live). It intrigues me as a
potential glaze component. I can get quite sandy material, although I don't
know the particle size distribution.

This material is quite orangey/brown. I'm making the assumption that the
color comes from iron content and hoping for some nice effects.

What can I expect the melting point to be?

Cheers, Linda

Mike Gordon on sun 8 may 05


I was thinking... after this discussion about using granite in glazes.
A friend of mine uses it for paths in his garden, " de-composed
granite" can be bought at the local gravel yard. I'm sure they would
give you a pound or two for testing, if your so inclined. Just a
thought. Mike Gordon

Paul Herman on sun 8 may 05


Hi Linda,

I use my local granodiorite as a glaze material. By itself, it will melt
and form a glaze at cone 10. I think you should test fire a sample of
your material, it's the best way to learn how much it melts.

I'm using a glaze with this formula:

100(?) mesh Granodiorite 40

Petersen feldspar (local material) 45

Whiting 5

Ball clay 10

At cone 10-12 it makes a speckly green celadon with a soft semi-matt
texture, and get's shinier at cone 13. It retains some of the character
of the stone, because I don't mill it very fine. Pottery customers like
the idea when I tell them, "This glaze is the Sierra Nevada, ground up
and put on a pot."

fortuitous prospecting,

Paul Herman

Great Basin Pottery
Doyle, California US
http://www.greatbasinpottery.com/

----------
>From: Linda Ferzoco
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: Granite
>Date: Sat, May 7, 2005, 2:07 PM
>

> Hi All,
>
> There's a kind of granite near me here in the San Francisco Bay area which
> is very crumbly from having moved about 300 miles north from the LA basin
> over the last kajillion years (the most extreme example of it is seen at the
> aptly named Devils Slide just south of where I live). It intrigues me as a
> potential glaze component. I can get quite sandy material, although I don't
> know the particle size distribution.
>
> This material is quite orangey/brown. I'm making the assumption that the
> color comes from iron content and hoping for some nice effects.
>
> What can I expect the melting point to be?
>
> Cheers, Linda
>

Linda Ferzoco on sun 8 may 05


Thanks for all the advice. I'm headed downstairs to make some test vessels
now. We have our final bisque firings next week and I've gotta get them dry
by Tuesday. Then mix up lots of experimental glazes.

Cheers, Linda