What are the glasses made of? November 18, 2022 13:33 Updated The glasses are made of crystalline glass (composed of sand, chalk, sodium and other minerals) and are lead free. Related articles Where are the Keltum glasses produced? Can I put my Keltum glasses in the dishwasher? Are the glasses breakable? Is it possible to return my order? What should I pay attention to when using my Keltum glasses?