This is a fabulous creamy moonstone glass lampshade from Fenton.  Fluted and ruffled with soft flowing hobnails, with a definite gorgeous brilliant opalescence to it, shaped like a fluted flower.  There are no chips or cracks.  It is 5" tall, approx 5.5" wide with a 2" fitter.  This is thick glass which is a characteristic of Fenton, they do not scrimp on glass.   I cannot find this lamp shade anywhere on the internet.  Unique, most likely rare.