Perhaps I have one of the platinum group metals, my cupels aren't following the rules so to speak. They never blink, they're bright gold when hot then as it cools its color fades to greenish gold but some dark greenish black towards the bottom. It also has a long pasty stage and hardens contracted. As it solidifies golden specs form on top not sure of depth looks like crystals forming? Since it never blinks I know not If all the lead is out of it. I would post some pics but I don't think it would do it justice on color and details unfortunately.