Natural stone is a material that is extracted from the earth. There are a wide variety of types of natural stone that can be used in coasters. The care and maintenance of these different types of stone requires different precautions depending on the chemical composition of the material being used. Not all stones are created equal, and it is important to understand the exact nature of the type of stone being used in order to understand how to care for its natural properties.

The classic stone for drink coasters is marble. Elegant, refined and sophisticated, marble is a material that has graced the architectural and artistic masterpieces of the human species for centuries. When used in drink coasters, the material is usually polished smooth, although it is possible to get them in a less slippery tumbled finish.

Caring for marble coasters is one of the most difficult types of stone to maintain. This is because marble is a solid base, in the acid base ratio. That means that if any acidic substance comes into contact with the marble, a chemical reaction will take place that will cause the stone to discolor. Fortunately, most marble coasters are treated with an invisible chemical sealant to prevent this, however, that doesn’t negate the fact that the sealant can wear off over time, leaving coasters vulnerable.

The best way to wash marble coasters is to simply use a non-scratch cloth, along with mild lukewarm water. Do not use soap or other chemical cleaners, as these are often acidic in nature. If you have a natural non-acid cleaning product, or a marble cleaning product, these can be used.

Slate is a much stronger and more durable material that is often used in the manufacture of coasters for drinks. In general, the board will not need much maintenance. Unlike marble, slate does not react as obviously to acidic substance as marble, although if something acidic gets on the coaster, you should clean it up immediately, as stains can form over time.

Sandstone is one of the most popular stone coaster materials available. It is highly absorbent, so when you place a sweaty glass on it, the moisture is absorbed into the stone and remains locked within the material until it can evaporate into the air.

The only problem with sandstone is that it absorbs all moisture, not just condensation. That means that if colored fruit juice is spilled on the stone, the liquid will penetrate the surface of the material and stain the stone from the inside, causing a mess that is almost impossible to remove.