Wade Blocker on thu 2 aug 01
Bill,
According to James Chappell, Lepidolite is a lithium-alumina silica
compound which is an important source of alkaline flux at temperatures
above cone 4. Good copper blues can be produced in such a glaze. It has no
effective substitute.
Perhaps it is no longer mined since none of the major ceramic supply
houses still carry it.Mia in cloudy comfortable ABQ
Bill Amsterlaw on thu 2 aug 01
Hi:
I have a potter friend in Connecticut with a closely-guarded glaze
recipe that calls for lepidolite. He has had a hard time locating a
source for lepidolite. He says he has done hundreds of tests trying
to find find a substitute recipe and he is not satisfied with any of
the substitutes. He would like to purchase a lifetime supply of
lepidolite if he can locate a source. Do you have any suggestions?
Thanks.
Bill Amsterlaw
Keene, NY
wamster@amsterlaw.com
http://amsterlaw.com/
Diane Winters on fri 3 aug 01
Hi Bill,
Hopefully you'll get some better info than what I'm supplying here, but the
following is what I came up with on the internet.
This is the URL of the page of Ceramic Industry magazine's Materials
Handbook which discusses lepidolite, also called lithium mica, (including a
typical chemical analysis) and mentions it's found chiefly in California,
Colorado, South Dakota, New Mexico, Zambia, Zimbabwe and Namibia.
http://www.bnp.com/cgi-bin/ci/Mat_Search/db_search.cgi
Unfortunately the CI directory of suppliers doesn't show any ceramics
industry mines/processers/suppliers currently listing it.
However, I did find this reference to a mine in a website by the U.S.
Department of the Interior Bureau of Mines MINERAL INDUSTRY SURVEYS
regarding gemstone production in the U.S.:
"Currently, the Stewart Lithia Mine near Pala [San Diego Co., California]
is the major supplier of lepidolite. Masses of the grayish-lilac,
purplish-pink, or pink lithium bearing mica from the Stewart mine often
contain sprays or sunbursts of pink tourmaline."
If you call, they might be able to tell you of anyone who's processing
lepidolite in a form usable for glazes.:
Stewart Lithia Mine
Mr. Blue Sheppard
(619) 742-1356
I know that's a long shot, so I hope someone else comes up with a better
source/solution.
Diane
in Oakland/Berkeley by the Bay - spending too much time in the studio and on
the computer today and not nearly enough enjoying a perfectly perfect day,
sunny in the upper 60's.
-----Original Message-----
From: Bill Amsterlaw
To: CLAYART@LSV.CERAMICS.ORG
Date: Thursday, August 02, 2001 3:21 PM
Subject: seeking source for lepidolite
Bill Amsterlaw wrote:
>I have a potter friend in Connecticut with a closely-guarded glaze
>recipe that calls for lepidolite. He has had a hard time locating a
>source for lepidolite. He says he has done hundreds of tests trying
>to find find a substitute recipe and he is not satisfied with any of
>the substitutes. He would like to purchase a lifetime supply of
>lepidolite if he can locate a source. Do you have any suggestions?
>
Janet Kaiser on fri 3 aug 01
Try a gem store.
We have an artist who sometimes uses lepidolite "rocks"
in her recycled cutlery windchimes, although amethyst,
carnelian, peacock ore, pyrites and others are more
popular.
Janet Kaiser
The Chapel of Art . Capel Celfyddyd
HOME OF THE INTERNATIONAL POTTERS' PATH
Criccieth LL52 0EA, GB-Wales Tel: (01766) 523570
E-mail: postbox@the-coa.org.uk
WEBSITE: http://www.the-coa.org.uk
Steve Mills on sat 4 aug 01
If Lepidolite is no longer being mined then this is a recent development
which we haven't heard of. We stock it at Bath Potters, it's not a big
seller, but there's always someone who wants some, so we keep it.
Steve
Bath
UK
In message , Wade Blocker writes
>Bill,
> According to James Chappell, Lepidolite is a lithium-alumina silica
>compound which is an important source of alkaline flux at temperatures
>above cone 4. Good copper blues can be produced in such a glaze. It has no
>effective substitute.
> Perhaps it is no longer mined since none of the major ceramic supply
>houses still carry it.Mia in cloudy comfortable ABQ
--
Steve Mills
Bath
UK
Hank Murrow on sat 4 aug 01
>If Lepidolite is no longer being mined then this is a recent development
>which we haven't heard of. We stock it at Bath Potters, it's not a big
>seller, but there's always someone who wants some, so we keep it.
>
>Steve
>Bath
>UK
Dear Steve;
You are fortunate to be blessed with a post-colonial government,
while we in the USA are just getting warmed up to the idea of colonialism.
Our government has placed a boycott on products from African countries
deemed inimical to our interests. Hence, no African Lepidolite. Perhaps
potters from the USA will be trucking over for a vvisit with you in Bath
and a full suitcase for the trip home!
Look Out! Hank in Eugene
cd on sat 4 aug 01
Using one of the glaze software programs it would not be a difficult =
task to reformulate the"secret glaze" using Spodumene as a sustitute for =
the Lepidolite. Lepidolite is a high potassium, low sodium, lithium =
feldspar. Spodumene has a shade more than twice as much Li2O as =
Lepidolite does, and is very low in both potassium and sodium. =
Depending on the other ingredients in the "secret glaze" the =
introduction of the potassium may be somewhat of a challenge, but I am =
sure there is a workable fix, may need to use some calcined Pearl Ash.
Cheers,
Craig
ILENE MAHLER on sat 4 aug 01
Where in Oregon.I have a potter in the middle of a set of dishes and
need it...Thanks Ilene
Hank Murrow wrote:
>
> >If Lepidolite is no longer being mined then this is a recent development
> >which we haven't heard of. We stock it at Bath Potters, it's not a big
> >seller, but there's always someone who wants some, so we keep it.
> >
> >Steve
> >Bath
> >UK
>
> Dear Steve;
>
> You are fortunate to be blessed with a post-colonial government,
> while we in the USA are just getting warmed up to the idea of colonialism.
> Our government has placed a boycott on products from African countries
> deemed inimical to our interests. Hence, no African Lepidolite. Perhaps
> potters from the USA will be trucking over for a vvisit with you in Bath
> and a full suitcase for the trip home!
>
> Look Out! Hank in Eugene
>
> ______________________________________________________________________________
> 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.
Hank Murrow on sat 4 aug 01
Craig wrote:
>Using one of the glaze software programs it would not be a difficult task
>to reformulate the"secret glaze" using Spodumene as a sustitute for the
>Lepidolite. Lepidolite is a high potassium, low sodium, lithium feldspar.
>Spodumene has a shade more than twice as much Li2O as Lepidolite does, and
>is very low in both potassium and sodium. Depending on the other
>ingredients in the "secret glaze" the introduction of the potassium may be
>somewhat of a challenge, but I am sure there is a workable fix, may need
>to use some calcined Pearl Ash.
Say, my analysis of Lepidolite has it very high in Lithium and very low in
both Sodium and Potassium, while having a serious quantity of Fluorine.
Silica to Alumina Ratio of 3 to 1.
Seems to me that a judicious addition of Cryolite to most any Spodumene
might get one close.
In my Shinos, I use Low Melt Spodumene with some Cryolite 'to taste'.
Cheers, Hank in Eugene
Bill Amsterlaw on wed 8 aug 01
Hello Clayart:
I am still in the process of gathering infomation on lepidolite
sources. A number of clayarters have written to me privately and I
have corresponded with a number of mining companies and other
resources. When it is all in, I send a summary to the list.
Unfortunately, I have had a major email problem with failure of mail
forwarding from my webhost to my isp - many messages lost in
cyberspace. If you have written to me over the past few days, please
send your message again.
Bill Amsterlaw
Keene, NY
wamster@amsterlaw.com
http://amsterlaw.com/
Ababi on wed 8 aug 01
Hello Bill.
Your struggling for the lepidolote reminds me of myself ordering "strange"
materials through the mail all the way from the USA because they interested
me,and the suppliers here thought I was weird (strontium carb,Cadycal
granular manganese ETC). YET it reminds me how I learnt through software
to change recipes and get the same or almost the same as the original ones.
If it is the first time you are going to make this recipe,start with a
substitution, have your own recipe with available materials.
Do you want me to make you a substation?
There is the way, to substitute the material, I prefer to change the whole
recipe, it makes life easier, and the numbers "nicer"
Ababi Sharon
ababisharon@hotmail.com
http://members4.clubphoto.com/ababi306910/
http://www.milkywayceramics.com/cgallery/asharon.htm
----- Original Message -----
From: "Bill Amsterlaw"
To:
Sent: Wednesday, August 08, 2001 09:42
Subject: Re: seeking source for lepidolite
> Hello Clayart:
>
> I am still in the process of gathering infomation on lepidolite
> sources. A number of clayarters have written to me privately and I
> have corresponded with a number of mining companies and other
> resources. When it is all in, I send a summary to the list.
>
> Unfortunately, I have had a major email problem with failure of mail
> forwarding from my webhost to my isp - many messages lost in
> cyberspace. If you have written to me over the past few days, please
> send your message again.
>
> Bill Amsterlaw
> Keene, NY
> wamster@amsterlaw.com
> http://amsterlaw.com/
>
>
____________________________________________________________________________
__
> 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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