This is a Vintage Macbeth-Evans Monax Uranium Milk Glass Art Deco Swan Song Open Sugar Bowl or Small  Vase. Made in the USA. Glows green under a black light. It measures 5 1/4" x 3 1/2". It is in good condition, with a few tiny chips/flea bites on the rim.  Please see pics for details. I enlarged a few pics to show the details of the chips. They are very small.