Popped round my mums today and she makes cards. on her table she had a craft catalogue and inside a selection of mica and powders used in card making. Now my little brain started ticking cos these powders are used for embossing so get exposed to heat and therefore could they be used on beads!!! ???
The Mica will work (I heard that the mica flames are fun!) I am not sure about the embossing powders though.
mmmm.. is the mica treated exactly the same as frit and enamels, just roll the bead in it place it in heat for a period of time(i will play) and then kiln it!
Mmm might get some of that and give it a go!
There's a chart somewhere of which pearlex colours work best I think - these will most likely be the same as the ones your mum has (I've got a drawer full of them!).
Here you go:
http://www.listen-up.org/kitty/beads/pearl/charts.htm
I don't know what the cosmic shimmer powders are like though - there are some gorgeous colours in their range.
Real mica is good, the soap-making powders work. And the flakes are fun too! Embossing powders are plastic though, so I wouldn't use them.
(http://i123.photobucket.com/albums/o297/weemaryanne/Mylampwork1557.jpg)