For sale is a brand new, never used, genuine and authentic: 
David Yurman Men's 20.9x18.5mm Mummy Wrap Signet Ring in Black Onyx and Sterling Silver
*being sold AS IS due to very small dings in sterling silver
-It lists for $1100
-Size 10
-Approximately 20.9x18.5mm smooth shiny black onyx stone set in sterling silver "mummy wrap" sterling silver band. 
-Band tapers to approximately 6.5mm at the back
-Inner ring marked with (C)D.YURMAN 925 
-The ring comes in a David Yurman gift box with a David Yurman Pouch, and certificate of authenticity.
-US customers: This item ships for FREE with USPS to the eBay Authenticity Program and then ships to you. Please allow for extra time in processing as this item will be verified by the GIA® through the eBay authenticity program.