Limestone is first and foremost a sedimentary rock. Sedimentary rocks are formed by sediment that is deposited over time, usually as layers at the bottom of lakes and oceans. This sediment can include minerals, small pieces of plants and other organic matter. Sedimentary rocks are deposited in layers as strata, forming a structure called bedding.
Limestones are composed mainly of skeletal fragments of marine organisms such as coral, forams (single-celled organisms with shells), and molluscs. The main minerals in limestone are calcite and aragonite, which are different crystal forms of calcium carbonate. There are different kinds of limestone that are used for different purposes, but only the hardest and densest should be used for countertops. (When subjected to extreme heat and pressure over time, limestone becomes marble!)
As a sedimentary stone, limestone is relatively soft and porous – to a degree. But not all limestone countertops are equally porous; some are extremely dense, and as such, liquids have a tough time penetrating. To minimize staining, apply a sealer periodically; even if the limestone gets stained, you can almost always remove the stain by using oxygen bleach (such as OxiClean). Oxygen bleach won’t harm the stone and will break apart the organic compounds that make up the foods and liquids that you commonly cook with (including red wine, grape juice, etc.). Like marble, limestone can be etched by acid, so don’t let mild acids such as vinegar or lemon juice sit for long periods of time. Limestone’s beautiful, almost creamy, appearance combined with thousands of tiny embedded fossils in it lead many to believe it is well worth the little bit of extra effort.
Here’s a look at some beautiful limestone countertops for your inspiration!