Thursday, July 19, 2012

Purple Crystal cone 10

Hey kids,  got this great tile as a accident in a workshop firing a light soda/salt cone 10 firing. But need some verification that it works more than once.

If anyone could try it and see I would appreciate it!

Haynes Base with 5% cobalt carbonate cone 10 soda

Nepheline Syenite: 45.00 Grams
Silica: 30.00 Grams
Whiting: 8.00 Grams
Dolomite: 10.00 Grams
Talc: 7.00 Grams
Total: 100.00 Grams
 Add : 5% cobalt carbonate 

Fire in light salt or soda


Sue Pariseau Pottery said...


Jesse said...

Any idea what the crystals are made of?

John Britt said...

The crystals are pyroxene crystals that you get from magnesium matt glazes (tea dust ) But not sure if they are reliable.

If they are too hot they will "melt" or if too much soda/salt the same thing.

But it was a spectacular tile!

Lee Marshall made it by accident. She up in 10x of the colorants I wanted but WOW!

June Perry said...

Magnesium crystals. Did you have tin in there? Tin with magnesium and cobalt can give pink/lavendar. If you charted the firing, you might be able to reproduce it.
I have one of Gay Smith's white, soda fired baskets with similar crystals. You might want to check with her to see if she can reproduce them in her glaze.


John Britt said...

No tin that I remember. Just the Haynes base I listed. It was an oxidation firing to a cone 10 at 3:00 but you know it could have been cooler since there is always variation.