search  current discussion  categories  materials - misc 

my local feldspar analysis

updated sat 30 jul 05

 

Ron Roy on thu 28 jul 05


HiPaul,

Thanks for sharing all this - an interesting spar.

I've compared it to my list of spars and the closest is Kingman - which was
also high in K2O - just what you want for those blue celadons.

Best regards - RR


>I have read old mining reports that said these particular feldspars were
>notably high in K2O, and from the way they behaved in the fire,
>suspected as much.
>
>From ALS Chemex, my two local feldspars came out as:
>
>P spar first, M spar second.
>
>SiO2 - 66.0 - 65.54
>
>Al2O3 - 19.0 - 19.03
>
>K2O - 12.03 - 13.55
>
>Na2O - 2.5 - 1.7
>
>Fe2O3 - .25 - .13
>
>CaO - .2 - .12
>
>MgO - <0.01 - <0.01
>
>Cr2O3 - <0.01 - 0.01
>
>TiO2 - 0.01 - 0.02
>
>MnO - <0.01 - <0.01
>
>P2O5 - 0.01 - 0.01
>
>SrO - 0.01 - 0.01
>
>BaO - 0.02 - 0.05
>
>LOI - 0.2 - 0.18
>
>Now according to what I read in the Laguna catalog, my local feldspars
>are way higher K2O content than anything I can buy down at the clay
>store. Around 10% is the tops. Isn't that interesting? My faith is
>restored. If you've gotten this far you must be some kind of feldspar
>masochist like me, and I'd love to hear your thoughts about the test
>results. What would you do with this stuff?
>
>Happy diggin',
>
>Paul Herman

Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513

Paul Herman on thu 28 jul 05


Hello All,

Gol durn it's been a struggle to get an analysis done on my two local
feldspars, both of which I have always had a lot of faith in. In trying
to get my materials tested though, I had almost lost faith (in professed
testers). I sent samples to a guy in Cornwall and never heard back,
except he sent me a nice book. I tried one of the assay companies down
in Reno ($100) and they used some kind of acid test and gave me an
analysis that made no sense, couldn't be right. The Nevada Bureau of
Mines (attached to U of NV) took my samples and 100 bucks and then after
a lot of weeks they said the XRF machine was broke and they didn't know
when the hell they were going to fix it. So they did an XRD test on it
instead, which told me that they were both K feldspar with a minor
amount of Na and silica, which was good to know, but I wanted percents,
you know?. So then I looked on the internet for XRF test, and after
emailing back and forth, sent four samples to a Prof at a University in
St Louis. That was a few months ago and I haven't gotten any response to
my emails. They didn't get my money yet. So, last week I went and
searched the internet again for XRF, and found an Australian
transnational company that does testing for the mining industry, and
they have an office in Reno for the gold mines. ALS Chemex is the
company, and they said "We can do it!" so I took them four samples, and
they sent them to the lab in Vancouver BC and did XRF on them. I paid
($120) and they emailed the analysis, which makes sense and pleases me a
whole lot.

I have read old mining reports that said these particular feldspars were
notably high in K2O, and from the way they behaved in the fire,
suspected as much.

From ALS Chemex, my two local feldspars came out as:

P spar first, M spar second.

SiO2 - 66.0 - 65.54

Al2O3 - 19.0 - 19.03

K2O - 12.03 - 13.55

Na2O - 2.5 - 1.7

Fe2O3 - .25 - .13

CaO - .2 - .12

MgO - <0.01 - <0.01

Cr2O3 - <0.01 - 0.01

TiO2 - 0.01 - 0.02

MnO - <0.01 - <0.01

P2O5 - 0.01 - 0.01

SrO - 0.01 - 0.01

BaO - 0.02 - 0.05

LOI - 0.2 - 0.18

Now according to what I read in the Laguna catalog, my local feldspars
are way higher K2O content than anything I can buy down at the clay
store. Around 10% is the tops. Isn't that interesting? My faith is
restored. If you've gotten this far you must be some kind of feldspar
masochist like me, and I'd love to hear your thoughts about the test
results. What would you do with this stuff?

Happy diggin',

Paul Herman

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

jesse hull on thu 28 jul 05


You wrote: What would you do with this stuff?
______________
Depends on how much you have.
If you'd be willing to sell/ offer a bit, say 250
grams, for running tests in my kiln, I'd be
interested. I'm not a foriegner to putting raw/
non-commercial feldspars through a test run. And I'm
more interested in making that one non-reproducible
piece, than only finding a glaze that works every
time.
If you look on my website, you'll see a blue crystal
on grey-streaked background (gallery page, center
image) that was a result of a successful firing with a
small batch of "found" feldspar a friend gave me.
Other attempts did not always come out so well, but
you don't know 'til you try.

WWW.JesseHull.COM

~jesse.

Michael Wendt on thu 28 jul 05


Paul,
I would jump for joy if I were you. First, you need to find out how much
there is and if it is already claimed. If not, file a mineral claim. That
way you can use it without getting into trouble and if you later decide to
market the feldspar, you will have the legal right to do so.
For now, gather the chunks and use a jaw crusher to reduce them to a
practical size for ball milling. Then ball mill them until they are as fine
as needed for glaze. I usually weight he raw ore before milling and mill the
amount needed to make a batch of the glaze I want. Then the rinse of the
balls and jar yields the needed spar for the glaze.
Regards,
Michael Wendt
Wendt Pottery
2729 Clearwater Ave
Lewiston, Idaho 83501
USA
wendtpot@lewiston.com
www.wendtpottery.com
Paul wrote:
I have read old mining reports that said these particular feldspars were
notably high in K2O, and from the way they behaved in the fire,
suspected as much.

>From ALS Chemex, my two local feldspars came out as:

P spar first, M spar second.

SiO2 - 66.0 - 65.54

Al2O3 - 19.0 - 19.03

K2O - 12.03 - 13.55

Na2O - 2.5 - 1.7

Fe2O3 - .25 - .13

CaO - .2 - .12

MgO - <0.01 - <0.01

Cr2O3 - <0.01 - 0.01

TiO2 - 0.01 - 0.02

MnO - <0.01 - <0.01

P2O5 - 0.01 - 0.01

SrO - 0.01 - 0.01

BaO - 0.02 - 0.05

LOI - 0.2 - 0.18

Now according to what I read in the Laguna catalog, my local feldspars
are way higher K2O content than anything I can buy down at the clay
store. Around 10% is the tops. Isn't that interesting? My faith is
restored. If you've gotten this far you must be some kind of feldspar
masochist like me, and I'd love to hear your thoughts about the test
results. What would you do with this stuff?

Happy diggin',

Paul Herman