Hollow glass shells

Now that summer has arrived, I've been thinking about beaches and beach combing and a recent issue of Soda Lime Times gave me some ideas for making shell beads, using hollow beads.  The results, still experimental are shown below:

The one in the lower left was made on a puffy mandrel, using two layers of glass, a transparent pin, and ivory.  I purposefully left one spot thinner than the rest, and as I kept blowing that spot ballooned out until it popped.  Then I played with the edges to produce a shell-like shape.  The others were made by first laying down a thin tube of pink (CIM Desert Pink).  Then I built up discs of ivory or CIM Butter Pecan at either end, pushed them together and let nature take its course in making a hollow bead.  When I achieved the shape I wanted, I heated one spot until glowing, then pulled that part of the bead with my pliers and when sufficiently cool, I cut it with nippers and opened up the resulting hole, again playing with the edges to mimic a shell.  There's plenty of room for improvement and improvisation!