Hi WenP, Jamey, Stef & all

My guess would be French glass beads combined with Galalithe (french spelling) cylinders (i.e. casein) on fox chain. Classic 1930's arrangement seen many times in different colours and art glass and Galalithe bead shapes. The necklace 'choker' length is 1930's. Louis Rousselet used this type of combination, but of course so did other french manufacturers of costume jewellery at the time.I can show various examples

WenP - can you show us a close-up of the clasp?

Cheers
Carole