agate stones in pottery

Hello all and thanks to all who responded to my agate stone question. I put 4
small "pebbles" into a bowl, bisqued it to ^04, and to my surprise----when I
unloaded the kiln there in the bottom of the bowl were the pebbles just like I
put them in. Nothing happened. I'm sure by firing them higher like to ^6,
maybe they would have melted, but I doubt it. So much for that experiement.
Martha

"Marmaj40" wrote in message
...
Hello all and thanks to all who responded to my agate stone question. I
put 4
small "pebbles" into a bowl, bisqued it to ^04, and to my surprise----when
I
unloaded the kiln there in the bottom of the bowl were the pebbles just
like I
put them in. Nothing happened. I'm sure by firing them higher like to
^6,
maybe they would have melted, but I doubt it. So much for that
experiement.
Martha

I guess you need to know what they are made of, at least mostly and what the
melting temperature is for that. Then you would get an idea if they will
melt or not.

On 28 Oct 2004 07:14:55 GMT, (Marmaj40) wrote:

Hello all and thanks to all who responded to my agate stone question. I put 4
small "pebbles" into a bowl, bisqued it to ^04, and to my surprise----when I
unloaded the kiln there in the bottom of the bowl were the pebbles just like I
put them in. Nothing happened. I'm sure by firing them higher like to ^6,
maybe they would have melted, but I doubt it. So much for that experiement.
Martha

I just looked up agate in a mineral handbook, and it said it was SiO2.

(silica). Looked up the melting point of pure silica... 1710C.
That's about cone eleventy-three, according to my calculations.

Best regards,


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com

Bob, I don't have that cone. :)

"Bob Masta" wrote in message
...
On 28 Oct 2004 07:14:55 GMT, (Marmaj40) wrote:

Hello all and thanks to all who responded to my agate stone question. I
put 4
small "pebbles" into a bowl, bisqued it to ^04, and to my surprise----when
I
unloaded the kiln there in the bottom of the bowl were the pebbles just
like I
put them in. Nothing happened. I'm sure by firing them higher like to
^6,
maybe they would have melted, but I doubt it. So much for that
experiement.
Martha

I just looked up agate in a mineral handbook, and it said it was SiO2.

(silica). Looked up the melting point of pure silica... 1710C.
That's about cone eleventy-three, according to my calculations.

Best regards,


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com

Oh dear ) Another type of stone maybe??

Martha wrote:
Hello all and thanks to all who responded to my agate stone question. I
put 4
small "pebbles" into a bowl, bisqued it to ^04, and to my surprise----when
I
unloaded the kiln there in the bottom of the bowl were the pebbles just
like I
put them in. Nothing happened. SNIP

Agate is essentially quartz with impurities that give it the color. As
someone else noted, quartz has a very high melting point. Glass is
essentially quartz with a sodium salt added which allows it to melt at much
lower temperatures, so agate COULD be used as a glaze but with a LOT of work
and research. I doubt you want to take the time to do it. Try putting glaze
on a test tile with a small agate in the middle. The higher cones the
better. The glaze may interact with the agate enough to stick to it.
Experiment, experiment, experiment. You will find all sorts of interesting
things.

Raj

"Bob Masta" wrote in message
I just looked up agate in a mineral handbook, and it said it was SiO2.

(silica). Looked up the melting point of pure silica... 1710C.
That's about cone eleventy-three, according to my calculations.

Best regards,


Bob Masta


Cute Bob G
It's actually cone 32

If anyone here needs info on cones, go right to the source:
http://www.ortonceramic.com/Resources/150c.pdf
You'll need Adobe Acrobat reader to view the files on that site under
resources, but the reader is free at :
http://www.adobe.com

What's REALLY nice is that you can print them out, and stick copies near
your kiln (but not too near, especially if you're trying for cone eleventy
three)

Happy Halloween, All Hallows Eve, Samhain, and whatever else you're
celebrating this time of year!

Wayne Seidl
Key West, Florida, USA
North America, Terra
Latitude 81.45W, Longitude 24.33N
Elevation 3.1 feet (1m)