I have been making soy candles for awhile now and often use glitter on top, but I have recently come across some candles that shimmer as you burn them. Does anyone know how this is done? Here is a video showing the effect I'm talking about, and here's another video. Does anyone know how this is achieved? I don't believe it's normal glitter and I'm leaning towards shimmery mica, although I've seen people say not to use it. If we were to use mica, how much might be used to make this happen? Thanks in advance!