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Iron Pyrite

Glaze Iron Pyrite Stoneware mid fire high fire Gold Silver

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#1 Boats



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Posted 11 March 2014 - 03:17 PM

Has anyone attempted to use natural iron pyrite in a clear base glaze to a mid to high fire on stoneware? I would like to use iron pyrite collected directly from area streams which may contain minute amounts of gold or silver. I would like to avoid having to completely reinvent the wheel. I have a propane updraft kiln.  Any advice or educated guesses are welcome.

#2 Tyler Miller

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Posted 11 March 2014 - 03:30 PM

Unfortunately pyrite isn't chemically stable at kiln temps, and its by-products are some nasty things (Hydrogen sulphide, sulphur dioxide, sulphuric acid).  When roasted it forms a less stable Iron sulphide which can ignite in air.


If you were to process it to be a usable ceramic material, you'd have some form of iron oxide.  I personally wouldn't bother with it.  It's a lot of semi-dangerous work for one of the cheapest pigments out there.

#3 neilestrick


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Posted 11 March 2014 - 03:35 PM



It can be used for speckling in glazes according to the above information.



Neil Estrick
Kiln Repair Tech
L&L Kilns Distributor
Owner, Neil Estrick Gallery, LLC

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#4 JBaymore



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Posted 11 March 2014 - 03:57 PM

The sulphur produced will likely be problematic.


Is local material usage worth the issues? Only you can decide.





John Baymore
Adjunct Professor of Ceramics; New Hampshire Insitute of Art

Former Guest Professor, Wuxi Institute of Arts and Science, Yixing, China

Former President and Past President; Potters Council



#5 Boats



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Posted 11 March 2014 - 04:09 PM

Thanks for the info. This will certainly save me a great deal of headache.  This alone paid for my membership fee, and then some.

#6 Marcia Selsor

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Posted 11 March 2014 - 05:21 PM

Gold is a colorant for ruby red glass. it may not give you gold flecks if that is the desired outcome.
Silver may turn black.
And yes sulphur can be a big problem.

Marcia Selsor, Professor Emerita,Montana State University-Billings

Also tagged with one or more of these keywords: Glaze, Iron Pyrite, Stoneware, mid fire, high fire, Gold, Silver

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