Granite and marble: porous natural stone
Granite is strong but porous to varying degrees, and much of it carries a protective sealer that reduces absorption and needs renewing now and then. Marble is softer and very sensitive to acid, so a single drop of lemon juice or vinegar can leave a dull spot called an etch.
To test porosity, put a drop of water in a hidden place: if the stone darkens quickly, it is absorbing and needs more protection.
What natural stone means
- It reacts to acids like vinegar, lemon and pickles
- It may need periodic sealing
- It tolerates heat better than quartz
- Etching cannot be wiped away
