Vintage Opera Length Stone and Bead Necklace,Gorg!

An absolutely beautiful vintage necklace, Opera length. It has a drop of 15 in. It is made of beautiful marble or jasper?stones and silver disc beads. There is no marking on the necklace found. All of my vintage is from my private family collection. This was in my great-aunt's belongings. I do not know what the stones are made of possibly they are not stones but they feel cool to the touch. Could be Jasper, Green turquoise or marble. Reminds me of Downton Abbey or the flapper era. :-)