Local artist, James Yaun, creates stunning blown glass objects, jewelry pendants, and cuff bracelets using borosilicate glass, 24k gold and fine silver, and a method called fuming.  Here is an excerpt from his own website, tcglassarts.com, explaining that process..."Most of my art objects are colored with 24 carat gold and fine silver through a process called fuming.  Fuming is a process similar to steam rising out of boiling water.  If you hold a cool plate over steaming water the steam will condense on the plate - so it is with fuming.  I take a small piece of 24k gold or fine silver and attach it to a small rod of clear glass then place it in the hot flame.  The precious metals get so hot they actually fume (steam) while I hold another piece of glass further back.  The fume rides the flame and sticks to this other piece of glass.  Most of my coloring is done this way, but I occasionally use pre-made glass colors.  The whites and light blues (a halo effect) are silver fumed, the pinks and oranges are gold fumed, and the yellows and greens are a blend of gold and silver."