George Shirley wrote in news:if6dnYvCX41urhnWnZ2dnUVZ snipped-for-privacy@giganews.com:
I hadn't thought of mineral deposits. Perhaps the OP's new sink has a surface texture that's more receptive to mineral deposits than his old sink.
I wonder if something like CLR might also work? CLR does a bang-up job of dissolving mineral deposits in our shower head.