Common Stone Issues
Scratching. There is a basic law when it comes to stone scratches—the harder the stone is, the more difficult it will be both to scratch and to repair. Essentially, in order for something to scratch stone, it must be harder than the stone itself. Soapstone or marble, for example, are relatively soft stones and could be scratched by a copper penny. Granite, on the other hand, is basically impervious to scratches from anything besides other granite and diamonds. Debris trapped on the bottom of your shoes may be enough to scratch some softer stones, so if you have a soft stone floor make sure to use rugs or mats near entryways and to sweep regularly. As for countertops, be careful not to slide your keys across the surface, as that is one of the most common culprits of marble countertop scratches.
Efflorescence. When salt-infused water rises up through the stone to the surface, the water will evaporate and leave behind a white, powdery substance. This is entirely normal, and it does not indicate a stain of any kind. Simply vacuum or dust mop the powder in order to remove it. Do not use water, as that will only exacerbate the problem. There are also cleaning products made specifically for efflorescence. This may have to be done several times, but eventually the stone will dry out and the efflorescence will stop.