While it is true that marble can withstand extremely high heat and pressure, it is still not advisable to place hot pans and pots on a marble countertop because they can alter and damage its surface. The inner core can remain the same and undisturbed, but the surface can form unwanted patterns or be left with scars and burn marks.
Placing hot pans on the surface can change the color of your marble countertop. This can be a nightmare especially if you have a beautiful white carrara marble. Marble is a softer material compared to granite, so its surface can change from the chemical reactions caused by heat contact. The color of the marble can help you determine its susceptibility to heat from hot pans. Scars or burn marks would not be very obvious on darker colored marble like pink, green, or brown than in white, peach, or beige-colored marble. So if you are a marble enthusiast and want to have natural marble for your kitchen countertop, get a darker colored one to better hide burn marks.
If you can avoid it, avoid putting hot pans or other heat-producing kitchen appliances directly on your marble countertop. You should always use a holder or a place mat where hot pans can be placed over. Heat can expand the marble pores and open them, making the surface absorbent to liquids that can stain it. Also, the metal and grits in the hot pans and kitchen appliances can scratch your marble surface when they are placed on it or dragged over it.
Marble countertops are high in maintenance. If you can manage it, do not do all your food preparations on your marble countertop. Cutting, slicing, dicing, and juicing can stain and scratch the surface. Doing all these things regularly can stress and destroy the marble finish. However, you can still use your marble countertop as a baking area. Kneading dough, rolling out pastries, and sifting flour on it do not give the surface as much stress as preparing food on it does. Just make sure that your baking tools are made of wood or plastic so they do not scratch or chip the surface.
One of the best ways to care for your marble countertop is by giving it periodic resealing every couple of years. Resealing can protect your marble from accidental mishandling. Should someone accidentally place a hot pan on it, then it has a lesser chance of getting marked or burnt if it has been sealed properly. Resealing also maintains your marble countertop's resistance to stains and makes it appear polished and like new. Contact your marble countertop contractor or manufacturer if you want to have your countertop resealed.
Remember that proper care and doing preventive measures can make the beauty and life of your marble countertop last.