Here's the recipe for the blue bead.
You need:
Clear
Transparent cobalt
silver foil
1. Make a base of transparent cobalt.
2. Add threaded clear stringer and melt in.
3. Wrap in silver foil and burnish.
4. Apply more threaded clear stringer.
5. Melt in slowly, watching for the robin's egg blue reaction.
6. Case with clear, keeping the base bead out of the flame.
You must be sitting right in your chair, the stars in the right alignment, and holding your mouth right. In other words, this is a really hard chemical reaction to reproduce.
Threaded Stringer
Heat a small gather of glass.
Out of flame, touch the gather to your bead and spin your bead to pull out thin strands of glass.