I believe the necklace you are showing is a Louis Rousselet design from the 1930's. Peter Francis' reference to a Pierre Rousselet is misleading - he got the first name wrong. The large spherical clasps with MADE IN FRANCE signatures were used by Rousselet in their designs.

The beads in your necklace are wound blue glass, lathe-turned and carved red galalithe (casein) and probably stained and carved vegetable ivory, all on the usual fox chain. These are classic combinations of beads made from different materials which he combined in this way.

The image of a necklace in my collection is a definite Rousselet design, and uses the same blue glass bead, some more lighter blue glass ovals and six now rather dirty-looking spliced casein beads which are a typical trademark bead of Louis Rousselet. These are fascinating beads made with a typical Art deco stepped design where originally black and blonde casein were spliced together and lathe-turned into an oval bead. I'll show another version of these beads in a second message.

The marbled effect in the oval blue glass beads looks similar to the marbled effect in the yellow beads you first showed.

Carole