This is Gem Classic David Yurman Ring , The ring is dainty and the band is a little over 2mm ,

David Yurman 

ESTATE DY Classic Gem Ring

Prasiolite

Cleaned & Polished 

Estimated Retail $495-$695

Specifications:

Ring Size : 7 ( this is a thin band so a half a size smaller is also fine )

Stone : Prasiolite faceted Checkerboard Cut , cushion

Measurements: 12mmx10mm  

Metal : 925 Sterling Silver Black Finish 

Band : Rope band black finish 

Hallmark : 925 

Signature : (c) DY

Collateral: POUCH

100% Authentic