What is limestone?
Limestone is sedimentary rock consisting mostly of organic material such as skeletons and shells of marine creatures and sediments. It is formed by material which settles to the bottom of bodies of water, and over millions of years, solidifies (lithophytes) into solid rock. Earth movements over extremely long periods of earth’s history can lift limestone miles into the air. The summit of Mount Everest is limestone that started out on an ocean floor.

Can I use limestone in my kitchen?
Like marble, polished limestone is subject to surface changes or damage from kitchen acids including citrus juices, vinegars, mustards, and so forth. Unsealed, some of the more porous limestone can be subject to stains. If the limestone is polished or semi-polished, you will see a rough spot where the substance sat on the stone. On a honed surface, such etches will be less noticeable.

Is limestone soft and chalky?
No, not at all. There are some limestones that are very hard and dense, nearly as hard and resistant as granite, and extremely non porous. Keep in mind, though, that these very hard limestones are still calcium-based and, if polished, are subject to damage from household acids. Mainly consist of calcite. It does not usually show much graining or crystalline structure. It usually has a smooth granular surface. Common colors are black, grey, white, yellow or brown. It is more likely to stain than marble. Limestone is known to contain lime from the sea water.