Granite countertops and easy to maintain and keep beautiful.  But they can dull over time if you use the wrong products for cleaning and maintenance.

Do not use products containing soap, chemicals or window cleaners to clean your granite.
It is best to use a pH neutral or slightly alkaline product.
Granite countertops may need to be sealed
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Natural stone such as marble, granite, slate, travertine, limestone and flagstone eventually become worn, dirty or stained and restoration is the process or returning the stone to the state in which it was installed. It may also entail the altering of the stone’s original factory finish to match a desired finish of the installation’s owner [...]