what does that.

pure silver or gold is what creates the color changing effects that will turn the pipe to darker shades of blue, green & gold over time, with use... I take a tiny piece of gold or silver and introduce it to a piece of glass above my torch. I do this when the pipe is just a round tube (we call it a point) with a opening on one side (and very hot) after i'm satisfied with the way the fume is turning out, I fuse the pipe into shape.