Wash the granite with water and detergent. Rinse well, dry with cloth and let air dry completely. Then use a granite cleaner and/or granite polish. Read instructions, may not need to use both at same time.

Granite cleaner and polish can be purchased at hardware stores or places like Lowes and Home Depot.

For day to day cleaning I use 50/50 solution alcohol and water. Granite does not streak and looks great for a long time before needing granite cleaner or polish.

Your table may not be faded, probably is dull. The granite cleaner and/or polish will bring back the shine if it was a polished granite to start with.

Real granite is a natural stone from the earth and to my knowledge does not fade. The finish can become dull.