Take 100 parts playground sand, 35 parts washing soda and 15 parts potassium carbonate - mix and grind together well in the trusty pestle and mortar. About 15 mins of grinding.
Prepare your kiln - A couple of flowerpots, one inside the other, fill with crushed barbecue charcoal.
Embed in this a ceramic crucible with lid and put you mixture in it. Cover and add more charcoal to cover the crucible.
Microwave on full power for 30-40 minutes.
Take care as it will be extremely hot, well over 1,000ยบ, when you remove it. Allow it cool and retrieve your batch.
![>:D](http://www.glassmessages.com/Smileys/classic/evil.gif)
Seen on one of those weird late night TV science programs.