Vintage Necklace Bead Material - Need help identifying

[estatecurios]

Does anyone know what material the large bead is made from? It is almost weightless in the same way cork does. 

[doodledog8]

What you have is a necklace from the 1970's and the large pieces are made of wood. Most of these were originally made of drift wood. Every well dressed fashionista (myself included) wore one !

We thought we were way cool.

[estatecurios]

Thank you!