I'm browsing eBay for my own entertainment. This stone looks strikingly like an August Vintage Cushion, to me:
http://www.ebay.com/itm/ESTATE-1900-ANTIQUE-ART-DECO-CUSHION-CUT-1-20CT-DIAMOND-TAPERED-BAGUETTE-RING-/370642803696?pt=US_Fine_Rings&hash=item564c085bf0
![_belk72__2k___kgrhqyokkqeq5inncgbbk8lf-d4mq___1.jpg _belk72__2k___kgrhqyokkqeq5inncgbbk8lf-d4mq___1.jpg](https://www.pricescope.com/community/data/attachments/318/318163-4867416e5b9f239f82bbd6943f4fc4b0.jpg)
http://www.ebay.com/itm/ESTATE-1900-ANTIQUE-ART-DECO-CUSHION-CUT-1-20CT-DIAMOND-TAPERED-BAGUETTE-RING-/370642803696?pt=US_Fine_Rings&hash=item564c085bf0
![_belk72__2k___kgrhqyokkqeq5inncgbbk8lf-d4mq___1.jpg _belk72__2k___kgrhqyokkqeq5inncgbbk8lf-d4mq___1.jpg](https://www.pricescope.com/community/data/attachments/318/318163-4867416e5b9f239f82bbd6943f4fc4b0.jpg)