olemus
Wiktionary:
3. the rim and flange which encompasses and fastens a jewel or other object, such as the crystal of a watch, in the cavity in which it is set

piltlikult
https://qph.fs.quoracdn.net/main-qimg-8887e43400c003701f9c91906b6439d0

https://i.pinimg.com/236x/89/47/ab/8947ab8da039cf08f2d84616bf8a8722.jpg

https://en.wikipedia.org/wiki/Bezel_(jewellery)