A small Bavarian village is renowned for its "Ruby Glass" glass blowing works. When the foreman of the works dies suddenly without revealing the secret of the Ruby Glass, the town slides into a deep depression, and the owner of the glassworks becomes obssessed with the lost secret.
"Heart of Glass" — movie produced in Germany and released in 1976. It has a good rating on IMDb: 6.8 stars out of 10. It is a feature-length film with a runtime of 1h 34min. "Heart of Glass" is currently available to stream on Amazon Prime ⎥ BFI Player. Click on a playlink to watch it now!