Vintage celluloid cameo/tortoise shell necklace-1940's/50's-lucite? bakelite?

Description

This is a vintage necklace that features a cameo.   I am not sure what it is made of but the cameo looks like bakelite or celluloid.  The rest of the necklace is a tortoiseshell look that could be lucite?  I am sorry for not knowing exactly what it is.  This belonged to my mother and I remember her wearing it in the 1950's, but it could be 1940's.  The cameo pendant measures 2 1/2" x 2 1/2" and the chain section (which is also plastic of some sort) is 12" long.  It is in excellent condition.  Please give this beautiful necklace a home where it will be appreciated.