Granite and marble are natural stones quarried from the earth. They have more in common than not, but for the homeowner wanting to enhance their kitchen countertops, there are some important things to consider.
The biggest difference is the porosity of the stone. Natural granite is a very hard, non-porous stone that is suitable for most kitchen countertops. When cutting things with a kitchen knife directly on a granite countertop, it will not leave scratches, which makes it a popular choice. It is also heat-resistant, unlike marble.
Marble is softer and more porous and leaves scratches from kitchen knives on the surface unless a sealer is applied. A sealer has a life expectancy of 10-15 years. It can also be applied to granite countertops, as well but is not a necessity. Manufacturers highly recommend a sealer for marble countertops