Stone Sink

I sink in the kitchen slate gray stone. It has a white film on him constantly. How clean?
The sink is only 6 months, the slate gray. It has a pump handle tap is contaminated antique finish. The film is not sticky and slimy. It is dry and white. I tried SOS magic eraser, soap … almost everything you can imagine. It looks great as it is wet and I'm cleaning, but when dry it is. Does anyone have this problem and if so, how clean it? Thank you. (Please, serious answers only useful) Sorry, I should have been clearer. It is of granite. Is sealed before installation. I'll check the websites. Thank you all for your answers help!
Have you used by chance, products that contain acids lemon, vinegar or stone? Who could dull the finish. It seems that the stone could not have been sealed. You may need to contact the seller of this problem. Meanwhile, here are some sites that deal with the cleaning of stone and marble counter tops to be the same process your sink. Good luck with soap and led me to some places much more …. I hope that helps …