Liz Claiborne Necklace

Unique necklace marked "LC" on hang tag. Although, it looks very much like silver, it is not marked as such. The pendant is solid on the back. The bottom portion of the pendant looks like a poured lucite/acrylic. The top part is a mystery to me - it looks like a natural stone, but I am sure it is just a man made material. It measures 16 inches and the extender will add an additional 4 inches if desired. The pendant measures approximate 1 3/4 inches in length and the green portion is 1 inch in width and the bottom portion is 3/4 inches in width. I will be happy to answer any questions or provide additional photos. I need your zip code to calculate the postage.