18" in diameter, 3 1/2" opening, 6 3/8" height. Thick glass, 1/8".
Unknown. Was told it was Tiffany my entire life.
Thank you for contacting Mearto with your appraisal inquiry.
Tiffany was one of several companies making stained glass and slag glass lamps in the early 20th century and certainly one of the more famous and most desirable. They're pieces were nearly always signed / stamped or labeled LC Tiffany, Tiffany & Co., or Tiffany Studios. - with shades they were marked on the rim. Can you take a look and let me know if this is marked and, if it is, take a photograph and add it to this inquiry?