I was gifted some glass goblets by a relative, and I would need to bring them back to my place on a Ryanair flight. Assuming that they fit in my cabin baggage (and probably taking on me the risk that they break), are they allowed onboard? In theory I see no restriction, but if they break (intentionally or not) they develop sharp objects, which are banned by Ryanair (and most probably every other flight company around). So how is the rule usually interpreted?
I am not sure what is your start point and destination. However, I will get the TSA rule that should be the strictest. Also, I am assuming that the rule to glass goblets is the same to glass cup.
You may transport this item in carry-on or checked baggage. For items you wish to carry on, you should check with the airline to ensure that the item will fit in the overhead bin or underneath the seat of the airplane.
To help officers get a clear look at your bag and reduce the need for additional screening, we suggest you pack your bag in neat layers (layer of clothes, layer of electronics, layer of clothes, layer of shoes, etc.) and wrap cords tightly around electronics items.
Even if an item is generally permitted, it may be subject to additional screening or not allowed through the checkpoint if it triggers an alarm during the screening process, appears to have been tampered with, or poses other security concerns. The final decision rests with TSA on whether to allow any items on the plane.