Ceramica

Ceramic links chip; they do not bend, and they cannot be resized conventionally

A ceramic bracelet is sized by removing links, never by adjusting them, and a damaged link is replaced rather than repaired. Expect chips at the link edges on a worn example and no scratches on the faces. A ceramic-appearance bracelet with bent links or scratch haze is coated metal.

Thermal behaviour separates ceramic from coated metal in seconds

High-tech ceramic conducts heat poorly. Held in the hand it stays cool markedly longer than steel, and it never acquires the warm metallic feel of a coated case. This is the fastest ceramic test there is, it requires nothing, and it defeats the common counterfeit — black-coated steel — outright.

A cracked ceramic case is damage, not a counterfeit indicator

Ceramic is hard and brittle. Dropped watches crack or chip where steel would dent, and the damage is generally not repairable. Record it as condition. It is also, incidentally, corroboration of the material: coated steel does not fail this way.