[Clayart] Crystals

[ronroy at ca.inter.net]

Hi Deb,

The silica we usually use is quartz - usually ground up and has sharp  
edges. If you use beach sand (quartz/silica) or desert sand the sharp  
edges are dulled and it does melt quite as fast.

The colour comes from small amounts of iron and manganese. You might  
notice some difference in colour if you were using it instead of  
ordinary silica.

RR

Quoting Deborah Thuman <debthuman at zianet.com>:

> I got to thinking. I do that now and again. I took a geology class a  
> year ago and learned that fast cooling makes micro crystals and slow  
> cooling makes macro crystals. Quartz is one of those fascinating  
> igneous minerals that does wild stuff. Amethyst is quartz. Quartz  
> can be clear. Quartz can be opaque?. Anyone here ever experimented  
> with using quartz in a glaze?  Not just silicon dioxide, but ground  
> up quartz? What happens if you use ground up amethyst in a glaze?
>
> Deb Thuman
> debthuman at zianet.com
> DebThumanArt.com
> https://www.spoonflower.com/profiles/deb_thuman
>
> You measure a democracy by the freedom it gives its dissidents, not  
> the freedom it gives its assimilated conformists.
>
> Abbie Hoffman
>
>
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Ron Roy
ronroy at ca.inter.net
Web page ronroy.net