Ron Collins on fri 8 dec 00
I would be interested to know if anyone can tell me if jade powder has =
any real use as a glaze material, and if so, would it be any good around =
cone 4-5. I have access to a pretty large supply here. Melinda in =
Guatemala
Snail Scott on sat 9 dec 00
At 05:35 PM 12/8/00 -0600, you wrote:
>I would be interested to know if anyone can tell me if jade powder has any
real use as a glaze material, and if so, would it be any good around cone
4-5. I have access to a pretty large supply here. Melinda in Guatemala
>
'Real' jade comes in two forms: jadeite and nephrite.
Jadeite is NaAl(SiO3)2: basically silica with alumina and soda.
Nephrite is Ca(MgFe)2(SiO3)4: basically silica with magnesium
and iron, and a little calcium.
Note that much of what's called jade is not. Even so, the stuff
might be useful. I'd start by treating is as flint, and see what
the other stuff does. Could be fun. Might not be totally
consistent from one batch to the next, especially if it's a
small-time producer, butanything that's easy to get and cheap to
buy is worth a few tests. Let us know how it works out!
-Snail
Khaimraj Seepersad on sun 10 dec 00
Good Day to All ,
Melinda ,
Jadeite uses chromium as its main colourant
Nephrite uses iron oxide .
Jadeite is supposed to fuse at 1050 deg.c
Nephrite goes much higher . In fact yesterday I
hit a piece of Nephrite with 1300 deg.c and
it didn't melt .
[ Nephrite is like a mix of talc and wollastonite ]
I will be testing both types in a few months as
glaze components -- just for fun.
These two Jades will lose their unique qualities
and become normal glass types .
I believe Jadeite has a similar chemical formula
to Nepheline Syenite ,save Green Jadeite is
coloured with chromium.
I would tend to think that Guatemala is jadeite
country ?
Hope this helps ,
Khaimraj
-----Original Message-----
From: Ron Collins
To: CLAYART@LSV.CERAMICS.ORG
Date: 09 December 2000 14:47
Subject: jade powder
I would be interested to know if anyone can tell me if jade powder has any
real use as a glaze material, and if so, would it be any good around cone
4-5. I have access to a pretty large supply here. Melinda in Guatemala
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Bret Hinsch on mon 11 dec 00
Anyone who wants to experiment with Chinese jade should beware - they might
not be using an entirely natural material. Chinese are very picky about the
color of jade - a small piece of jade with a particularly rare shade can be
sold for thousands of dollars here in Taipei. As a result, the jade in
Taiwan is often dyed to fool the unwary. I'm sure that these artificial
colorants will skew any glaze test results, so be careful that the jade
you're using is really natural. Cheap Chinese jade that has been processed
into bracelets and other items is particularly suspect.
Bret
>From: Ron Collins
>Reply-To: Ceramic Arts Discussion List
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: jade powder
>Date: Fri, 8 Dec 2000 17:35:39 -0600
>
>I would be interested to know if anyone can tell me if jade powder has any
>real use as a glaze material, and if so, would it be any good around cone
>4-5. I have access to a pretty large supply here. Melinda in Guatemala
>
>______________________________________________________________________________
>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.
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Khaimraj Seepersad on tue 12 dec 00
Good Day to All ,
Bret ,
can't agree with you more . I bought a cheap piece the other
day and the most noticeable quality was the wax holding in
the Yellow Food Colouring .
A soak in Methylated spirits for 3 days removed most of it .
To reveal a highly translucent [ rock ] dull green in appearance,
as hard as a steel knife --- Nephrite ?????
When I subject some Burmese Jadeite to 1280 deg.c , I will
know just how fusible / meltable this Jade is.
Fortunately you can buy Ice Jade [ Jadeite ] for very little , and
there is no added colour [ of course is it jade ???? ]
Thank you for the sending .
Khaimraj
-----Original Message-----
From: Bret Hinsch
To: CLAYART@LSV.CERAMICS.ORG
Date: 11 December 2000 20:20
Subject: Re: jade powder
>Anyone who wants to experiment with Chinese jade should beware - they might
>not be using an entirely natural material. Chinese are very picky about
the
>color of jade - a small piece of jade with a particularly rare shade can be
>sold for thousands of dollars here in Taipei. As a result, the jade in
>Taiwan is often dyed to fool the unwary. I'm sure that these artificial
>colorants will skew any glaze test results, so be careful that the jade
>you're using is really natural. Cheap Chinese jade that has been processed
>into bracelets and other items is particularly suspect.
>
>
>Bret
>
>
>
>
>>From: Ron Collins
>>Reply-To: Ceramic Arts Discussion List
>>To: CLAYART@LSV.CERAMICS.ORG
>>Subject: jade powder
>>Date: Fri, 8 Dec 2000 17:35:39 -0600
>>
>>I would be interested to know if anyone can tell me if jade powder has any
>>real use as a glaze material, and if so, would it be any good around cone
>>4-5. I have access to a pretty large supply here. Melinda in Guatemala
>>
>>__________________________________________________________________________
____
>>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.
>
>___________________________________________________________________________
__________
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http://explorer.msn.com
>
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___
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>
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>
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melpots@pclink.com.
>
June Perry on tue 12 dec 00
Dear Bret:
All jade is not jade is correct. A lot of that cheap, so called jade is
actually aventurine; but I don't think it is necessarily a rip off from their
point of view. Some other jades, aren't jade at all either. It is my
understanding that in China, it is common to call many type of stone jade.
Nephrite jade is the non precious form of jade. It is a calcium magnesium
calcium iron silicate. The precious jade, jadeite, as someone else posted, is
a harder stone and is more like a Nepheline syenite in its composition.
I don't know what materials are used for coloring some of the stones, but I
think that you would have to start with a pretty porous stone to be able to
dye it. I do know that in the jewelry industry, semi precious and precious
stones are heated to intensify the color. They do this with everything from
inexpensive blue topaz to sapphires.
Regards,
June (an old rock hound)
Ron Collins on tue 12 dec 00
June,
My husband is also a rock hound/geologist/ that's what got us here in the
first place...here in Guatemala, it is jadite...I will try it out...I have
been told, use it as a sub for silica, I'll try that...I'm no glaze expert,
and never wanted to be, that's my least favorite part of ceramica
anyway....mi esposo is tonight off in the mountains and cloud forests with
the owners of the jade factory on a buying and identifying trip...that's why
I have access to so much jade powder-mixed with polishing rouge I imagine
(is it similar to graphite? Ron would know, but he's not here for a while)
anyhow, when I try it as a substitute, I will compare the two and post it,
as I have had some correspondences about it....Melinda in GT.
Ron Collins on tue 12 dec 00
Khaimraj-
Thanks for you input...here in Guatemala, it is jadite...I'll test a recipe
or two with both silica and jadite as a sub...if indeed it does melt at 1050
C, then it might work for me.....I'll post my results....do the same, and
maybe I'll have something that I can use down here..say, you seem to know a
lot about a lot, or maybe like me, a little about a lot....Melinda
iandol on wed 13 dec 00
This is so. Some of the finest green jadeite sold and exported from the =
Oriental is South Australian Chrysoprase, a cryptocrystalline quartz =
coloured with sufficient nickel to make it a valuable metallic ore in =
it's own right. Superb translucence, vivid colour and a delight to cut =
but rare in solid form since it often contains many small cavities lined =
with microcrystals. I made a ring from a twelve carat stone I cut. Value =
it more than jade. We also have one of the Worlds largest prospects of =
Nephrite at Cowell. The black variety is being exported to make funery =
urns. D'ya wanna know 'bout the sapphire scam?
Ivor. South Australia.=20
Snail Scott on wed 13 dec 00
At 08:12 PM 12/12/00 -0600, you wrote:
>I have access to so much jade powder-mixed with polishing rouge I imagine
>(is it similar to graphite? ..Melinda in GT.
>
Jeweller's rouge usually contains some
iron oxide.
-Snail
June Perry on thu 14 dec 00
Melinda, if it is truly jadeite, then that is a sodium alumina silicate with
a formula of NaAlSi2O6.You might be better off using it as a substitute for
Nepheline Syenite rather than a substitute for straight silica.
Regards,
June
June Perry on thu 14 dec 00
Melina, I don't know what is in the polishing rouge, but I know from the
stain on my clothes that it's loaded with red iron oxide. The jade/jadeite
may already contain iron and you may not want to add more to you recipe along
with other unknowns.
Sometimes titanium is used as a polishing agent and it's possible that the
rouge may contain that as well. It could also contain pumice.. I think it
would be best to stick with your experimenting with the jadeite powder and
see what that does alone before adding other unknown ingredients.
I don't know what temperature you fire at, but if what you have is a true
jadeite, you might get an interesting shino out of it by just using 80
jadeite and 20 ball clay if you're working at cone nine or ten. It might give
you a glaze with 85 jadeite 10 whiting and 5 clay if you're working at cone
10 and maybe a crackle or clear with 85 jadeite and 15 whting.
If you have the Ian Currie's book, or go to his website, you can use his
method of testing and run some of his 35 block tests on this material. If
it's a material that is readily available to you, I think it would be time
well spent for you.
Regards,
June
Snail Scott on thu 14 dec 00
At 06:45 AM 12/14/00 -0000, you wrote:
>>iron oxide.
> -Snail>
>
>I was under the impression that jeweller's rouge WAS iron oxide, Fe2O3.
>Any jeweller's out there?
>
>Martin Howard
>
The gritty bits are iron. I'm not sure what the
oily binder material is, or what it might contain,
though.
-Snail
Richard Jeffery on thu 14 dec 00
Ivor
wife's a jeweller
think I should know.....
-----Original Message-----
From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.CERAMICS.ORG]On
Behalf Of iandol
Sent: 13 December 2000 07:17
To: CLAYART@LSV.CERAMICS.ORG
Subject: jade powder
D'ya wanna know 'bout the sapphire scam?
Ivor. South Australia.
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Martin Howard on thu 14 dec 00
iron oxide.
-Snail>
I was under the impression that jeweller's rouge WAS iron oxide, Fe2O3.
Any jeweller's out there?
Martin Howard
Webb's Cottage Pottery
Woolpits Road, Great Saling
BRAINTREE, Essex CM7 5DZ
England
martin@webbscottage.co.uk
iandol on fri 15 dec 00
It would be unusual for jade to be polished with a red powder so I think =
jewellers rouge is not the substance being talked about. The =
recommendations are for Chrome oxide, Cerium oxide or Tin oxide. Not all =
jewellers rouge is red. Some are white. Jewellery and lapidary are =
different crafts. They may have a common vocabulary, but we all know =
about the confusion of words.
Ivor Lewis, Redhill, South Australia.
Ivor Lewis
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