A silver lined crystal bead in the larger 5/0 size.  These are round beads, larger than the 6/0s :  the 5/0s are about 5mm wide and 6mm long with a hole of 1.6 mm and will slide nicely on somewhat thicker yarns like worsted weight.

There are only about 7 beads per gram.  We are packing them in containers that hold roughly 20g.