Nowadays there are several types of stained glass lamps, and people usually call them Tiffany, whereas most probably they are not. Most probably they are Tiffany reproduction lamps. However they strongly resemble the originals with the properties mentioned above. The better naming for these are 'Tiffany style lamps'. You can easily find good quality reproductions that can make any home proud, however at the same time there are many low quality, cheap replicas that do the real lamps shame. You should stay away from those.