In the interest of managing the consumption of megabits this gold video only shows 1 of the 2 major lines.

Image captured in poor sunlight with digital camera.
This red color is not what it appears to be by normal eye sight and can only be better viewed under a microscope.
When ever I see this red coloration (sublimate) on the ceramic boat I am alerted to the possibility of gold being present in mineral samples.
The yellow color is a much thinner flash coating of metallic gold.
The black color at right is from the carbon electrode.

8x – Image captured with microscope digital camera connect to computer.
This low magnified view of the preceding image shows how the red color is actually a very thin film of gold that was volatilized by the electric arc from the impure gold bead.
The microscope was focused upon the red coloration and not the gold bead.
The gold coloration surrounding the gold bead is actually zillions of tiny spheres of gold.