Vintage Diorios Egyptian revival enamel book chain necklace

Vintage Diorios Egyptian revival enamel book chain necklace, the oval pendant is topped with a trio of ancient figures against an iridescent dark blue cold painted enamel background and a sickle of turquoise blue, broken fold over clasp replaced with a fancy toggle, my research shows this style may have had a large piece attached to the pendant that broke off but you can’t tell, comfortable on/sits nicely on the neckline, has mild age/wear, very unique style and highly collectible in the jewelry world, 18” long. 6796