You should always seal cut countertops to prevent damage and to keep them looking their best. The right way to seal countertops depends on the type of material. For laminate and wood, apply epoxy or other specialty sealers by pouring it onto the countertop and letting it flow across the whole surface to the edges, guiding it with a paint stick or putty knife. You will need to move quickly so that it does not dry or harden before you are done. For stone countertops, use a sealant specially manufactured for your type of stone and apply it according to manufacturer directions. 

Marble is high maintenance, like most other types of natural stone flooring. However, because it is naturally a more porous stone, there are a few added care instructions. You will need to clean it often to prevent dirt and grit from scratching the finish and surface, keep it dry, clean up spills immediately, and have it professionally sealed and refinished at least once a year to maintain the shine and water-tight surface. However, investing in maintenance is a smart move because marble floors are among the most beautiful and valuable types of flooring when properly cared for.

Yes, stains can often be removed using a poultice paste that draws out the stain. The paste is applied, allowed to dry, and then removed, lifting the stain from the stone.

Marble is a porous natural stone that needs sealant to minimize staining. Leaving this type of countertop material sealant-free means any liquids left on the surface will quickly absorb into the stone, discoloring it and dulling the sheen. Dark or acidic liquids, like red wine, coffee, and lemon, are the worst culprits.