A localized mark left where a water droplet or small wet area dried and concentrated dissolved or suspended material.
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Meaning and boundaries
A water spot can be removable residue, an adhered deposit, or a location where chemical alteration occurred. Appearance alone does not establish which condition is present.
Why it matters in glass restoration
Spotting pattern and response to controlled cleaning help distinguish a deposit problem from etching, coating damage, or another form of haze.