•The secret to cool bodies and glazes is alot of testing.
•The secret to know what to test is material and chemistry knowledge.
•The secret to learning from testing is documentation.
•The place to test, do the chemistry and document is an account at https://insight-live.com
•The place to get the knowledge is https://digitalfire.com
Anhydrous Ferrous Sulphate FeSo4, Calcined Copperas
||If this formula is not unified correctly please contact us. |
Has been used in glazes as a substitute for red iron oxide.
There are varying ideas from country to country about what this material is. Historically it was just a naturally-occurring red iron oxide containing impurities (i.e. clay minerals) or an ultra-high iron clay. Today, Crocus Martis sold by ceramic suppliers is more likely to be a soluble synthetic impure red iron sulphate or a calcined-at-900C version of the sulphate (it is insoluble). This material is not normally highly processed and therefore can produce iron specking in glazes. Normal iron oxides can be used as a substitute (although less will be needed since this material has a significant weight loss during firing).
Sulphur is released during firing and it does not decompose fully until as high at 1200C.
Out Bound Links
In Bound Links
XML for Import into INSIGHT
<?xml version="1.0" encoding="UTF-8"?>
<material name="Crocus Martis" descrip="Anhydrous Ferrous Sulphate FeSo4, Calcined Copperas" searchkey="" loi="20.88" casnumber="">
<oxide symbol="Fe2O3" name="Iron Oxide, Ferric Oxide" status="" percent="41.640" tolerance=""/>
<oxide symbol="FeO" name="Ferrous Oxide" status="" percent="37.480" tolerance=""/>
<volatile symbol="SO3" name="Sulfur Trioxide" percent="20.880" tolerance=""/>
Copyright 2003, 2008, 2015 https://https://digitalfire.com, All Rights Reserved