Feel free to check out more Antique Architectural Hardware in My Ebay Antique Shop. I'm a Maine Picker listing items weekly from Barn, Farmhouse and Mill Building Calls. Thank You for Visiting! 
   Up for sale is a C.1920 Mercury Glass Door Knob. No Chips or Cracks in Glass! This inside surface will have some voids and pitting. Naturally distressed and authentic old hardware. Threaded spindle hole in shank will have a chip around the edge. Threads are another 3/8" deep and should not be an issue with functionality. Surface will have light scuffs and/or scratches. 
2 1/4" Diameter, Depth 2 3/16"
Please Look at All Pictures and Read the Condition Section.