Ceramic bezels can be damaged. Someone on another forum posted a photo after dropping a ceramic bezel Sub onto a non-carpeted floor from a height of 3-4 ft. There was a picture of the bezel in 2 or 3 large pieces. However, I'm not sure the ceramic will wear off, as its a ceramic insert and not a ceramic coating. Rolex says there are light coatings of platinum or gold that are applied to the graduation markings on the bezels, and I think those could wear off over time.
The owner of Linde Werdelin, was qoute in an interview saying, that the coating on their Spidos wouldn't last "forever".
Any vintage zenith experts on here?