This is design 5580A by Margot de Taxco. It is an excellent example of how Margot worked her designs into more function than any other Maestro of the Spratling Era. The drop unhooks and turns into a brooch that is 1.75 in. long. The links have heft and dimension as they are
.25 x.25in. boxed shape repousse with hand made bead ornamentation. The weight is a generous 50 grams of repousse. The wearable length is about 16in. with a curve at the drop that makes it hard to be exact. The presence is stunning and I will let the pictures say the rest, just LOOK AT THAT NECKLACE!