Hi there,
I'm wrong more often than I'm right - but this has been my working theory:
The top 4 rows of beads pictured here are from shells of some sort.
The bottom 5 are some sort of coral.
Beadman, perhaps you can confirm that the deep pink beads are angel skin coral or some other material?
The bottom 4 (bottom 3 in 2nd photo) seem to be a very similar white coral-like material with pink bits. They may well be shell - though the beads that are flushed a little pinker over all have striations in them that are similar to what we see in redder corals. this fine detail has proved impossible for me to photograph so far, unfortunately.
I hope that the pictures help provide a sense of the materials. It is always way more fun to have them in hand.
Cheers.
Linda