I tried to make a coaster just to see what would happen with the gold powder. I used different colored frit and added the powder to it between two 3″ clear glass circles. The edges fused before the frit and powder melted and a gas occurred in the middle of the circles creating a bubble that is at least 1 1/2 to 2 inches across and 1/2 inch high. The glass in the middle of the bubble didn’t melt but created a rattle. I did find out that the “gold” powder is mostly copper. I have a beautiful blue “blob” on one side and you can see copper splotches on the underside. Although it really looks cool and I won’t be doing this again curiosity wants me to to see what I’d get next time.