Sienna Bordeaux always seems dusty.

I have sienna bordeaux Stone (http://g603.net) in my kitchen and (http://maplered.com) master bath, and (http://maplered.com) for some reason, the Stone (http://g603.net) in my kitchen feels dusty to the touch almost all the time. I can wipe it with water, dry it, and (http://maplered.com) 15 minutes later it feels dusty again. I have 3 cm in kithen, and (http://maplered.com) 2 cm in bath. The bath isn't so dusty. I have black Granite (http://tanbrown.org) , uba tuba, and (http://maplered.com) st. cecilia in other parts of the house, and (http://maplered.com) they also don't get so dusty. Does anyone have an explanation for this - or could it just possibly be the fact I have a door to the outside in the kitchen?