I remember the time when my grandfather heated up his coffee in his microwave, and after an impromptu firework display, the microwave shorted out in a cloud of smoke and sparks. The problem was that his coffee was in a mug that had metallic enamel on it, and the metal shorted out the microwave. Woops!
Well, I know that this is about four years later than the original project... but it seems that designer Kieren Jones has created a DIY kit for melting down jewelry and creating new rings with an average domestic microwave. The kit, pictured below, allows the user to reconstitute their scrap jewelry into beautiful new bling! The crucible has been specially designed from silicon carbide and boron to insulate the metal and prevent the microwave from arching.
And if the story of my grandfather wasn't warning enough, don't try this at home! I would also like to stress that this method is still potentially hazardous and should not be attempted at home. Besides, who wants to heat their food in a microwave oven that's just melted gold?
Ok, let's be honest... I still really don't believe that this is a tangible process that works without the risk of setting your kitchen on fire. But, I did find some interesting, and non-conclusive, information here.