Thanks for saying so! It suprised me aswell when I found out they were hot enough - I was so happy I didn't need a special torch for it. 10k melts at a higher temperature than silver, but 14k has a lower melting temp. Then 24k has a higher melting temp. The borax acts as a flux to get the heat even through all the metal, and also attracts impurities to make the metal purer. Although I started with 10k it will likely test higher on a nitric acid test, due to melting it with borax. Its quite neat, once everything is said and done - the borax has melted into a layer of glass.