Marble is a porous material, which means it has pores, or tiny holes in the makeup of the stone that air and liquids can be absorbed into. This can be a problem in kitchens, where spills are common. So generally speaking, yes marble should be sealed. How often depends on the stone and sealing process.

Marble has a high heat tolerance, but you should not put extremely hot items directly on the stone. A pot or pan right off the cooktop for example, could cause a thermal shock that will crack the marble. Extreme heat can also cause a noticeable color change or minor burn mark on the stone. This is true of most natural stones. You're not likely to have an issue if you do put something hot on your marble countertop, but it is recommend that you let items cool down or use trivets and coasters to be safe. If you're looking for a stone with better heat tolerance than marble, try granite.

Use a non-abrasive dish soap and warm water. You'll want a pH neutral soap, as acidic cleaners can harm marble. Apply a thorough covering of the soapy water and scrub gently. Don’t use rough scrubbing cloths, just a soft towel. The, use a fresh damp cloth to wipe away the soap. Repeat this step until all of the soap residue is gone.

Polished marble is has a shiny, high-gloss look. It's very smooth and it's coating acts as a protectant. Honed marble is a flatter finish, it's less reflective. People often choose honed marble because it is less likely to scratch or etch. A scratch on a matte surface will usually be less noticeable than on a shiny finish.

Granite and Marble are similar in many ways. They are both natural stones, and except for very high-end applications they are close in price. The main difference between marble and granite for many people is simply the look. Marble offers a classic, elegant look that is hard to match. It is one of the lightest and brightest natural stones available. While it is slightly more difficult to maintain, marble has luxurious, high-end feel that can't be replicated.