Dampen a nonabrasive scrubbing pad with water and apply 2 or 3 drops of mild dish detergent.
White rings around faucet on granite.
When hard water sits on a granite surface and dries it leaves a visible mineral deposit that often creates white rings especially around faucets.
For really stubborn stains try using a poultice or extractor.
Poultice products made especially for granite can be purchased at a hardware or stone surface specialty store or you can make your own paste using flour plus hydrogen peroxide.
I get that they do not sit directly on the granite but soapy water certainly does get onto the granite particularly around the soap bottle and sponge.
A water filter may not be sufficient to deal with hard water.
For this kind of stain use a specially formulated granite cleaning product like granite gold daily cleaner and scrub with a soft bristled brush then rinse and dry with a soft cloth.
Scrub the granite sink with the scrubbing pad.
Hard water can create a calcium buildup which is also called limescale or lime deposits.
Maybe they used plummer s putty at your faucet connections.
These are formed by the water that flows into the home and is fairly common in most cities.
It was deemed not a good idea as a plummer s putty ingredient tends to bleed through granite and leave the type rings you describe.
It had to do with using plummer s putty to seal faucets at stone level.
Hard water stains around the faucet.
The ugly white or yellowish rings around the faucet base aren t unusual.
Rinse the granite sink thoroughly with hot water.
For those tenacious water rings around a faucet resulting from hard water that sits on the surface try scrubbing softly with a brillo pad or gently scraping with a razor blade then wiping away the residue with a soft damp cloth.
You need a water softening system.