My grandparents always drank tea from a glass, the yiddish:

A "Yiddish glass of tea" (a glezel tey) is a traditional Eastern European Jewish staple, typically served hot in a glass rather than a cup, often with a metal holder. It is historically associated with sipping through a sugar cube held between the teeth, accompanied by lemon, jam, or sweet pastries.

Cultural Significance: Drinking tea from a glass was standard, often signifying warmth, hospitality, and a simple, comforting staple of life.
How to Serve: A teabag or tea leaves are placed into a heat-resistant glass—often with a metal holder (podstakannik)—and filled with boiling water.
"Glazel" Context: The word glezel refers to a small glass, with the phrase often evoking nostalgia for old-world traditions.
"Glass of Tea" Culture: In Eastern Europe, tea was sometimes served with a piece of sugar broken off from a larger sugarloaf. It was commonly enjoyed while listening for the cracking sound of sugar and without stirring.

Interestingly, when we lived in Iceland, we found the Icelanders often had the same tradition of holding a cube of sugar between their teeth and sipping the tea through it.