How you can clean a stone hearth

Trisodium Phosphate (Teaspoon) durable cleaner – offered at most hardware stores.
Bleach
Tepid to warm water
Bucket
Sponge
Stiff bristled brush
Old blankets or towels
Plastic tarp
Duct tape
Rubber mitts
Eye protection

Steps to wash the Stone:

Put on rubber mitts and eye protection whatsoever occasions.
Mix an answer of Teaspoon (trisodium phosphate) in tepid to warm water within the bucket based on package directions. The dirtier your hearth, the more powerful you need to help make your solution.
Add 2-3 ounces of bleach per gallon of solution.
Lay the plastic over or round the hearth to safeguard the actual floor. Seal round the edges with duct tape to avoid leaks.
Pile blankets and/or towels round the place to catch runs, drips, and overflow while you scrub.
When the hearth is heavily soiled, wet it lower using the solution utilizing a sponge to permit the detergent to start working before you begin to wash.
Next, attack using the scrub brush. Deep, hard scrubbing is going to be needed on porous stone. Eye protection is essential here, because the scrubbing process will be sending tiny droplets flying! You might want to keep the mouth shut too.
If stains are persistent, create a paste water and Teaspoon and apply straight to the stone. Scrub liberally.
Finish by sponging water that is clean within the stone, all the way through, like a rinse.
When you’re pleased with the cleanliness from the stone, let it air dry before taking out the blankets, towels, and plastic.

Resourse: http://howtocleanstuff.internet/how-to-clean-a-stone-hearth/

Sam Cashman: What if the black has turned gray in places? Is this the natural look or is the color fading?

Shelly Minutillo: Super helpful! Thank you! I've been looking for a solution for years! Thanks guys!!