multiple dull spots on new marble

Very recently an Arabescato Marble countertop has been installed in my kitchen and within a few days  d u l l   s p o t s  appeared on the highly polished surface and now, after 4 weeks there are just a hundred dull spots. I would like to find out how to rectify this damage & how to prevent it in future. I was told ( by the installer) that acid substances as in lemon juice and similar items related to food preparation would damage the luster of the polished surface. My own observations do not substanciate this claim. Further, I have a dining table of the same material in use since 15 month with no damage to the polished top. Can anyone give me an opinion on this topic please? Thanks Erich