Exactly what are "ceramics"? I found a lot of similar "definitions" of that term online, e.g. on Wikipedia and here.
These (and other) sources essentially state that ceramics are non-metallic, non-organic materials. And they state the most prominent examples.
But these only seem to be necessary properties. Are there sufficient criteria based on which one can definitely decide whether a certain material is ceramic? Is this list of criteria comprehensive?
Is there even a widely accepted clear definition at all?