Calcareous vs. siliceous stone: What’s the difference?
Back in school, when studying geology, you probably learnt about the three most basic types of rock: metamorphic, sedimentary and igneous.
What you might not have learnt is the fact that each of these categories can be further split into types: calcareous and siliceous. Depending on which type your stone qualifies as will have an impact on the method of surface cleaning you can successfully utilise.
As the Marble Institute of America tells us calcareous stone is made chiefly from calcium carbonate. This is a chemical compound that is typically found in items such as pearls, shells and, of course, natural stone.
Such stones are particularly sensitive to acidic solutions. This has a couple of important implications. For one, it means that you can't use acidic cleaning products for stain removal on calcareous stones. Secondly, it means that you have to be wary of handling acidic liquids around such stones, such as fruit juice containing citrus or alcohol.
Examples of calcareous stones include marble, limestone, onyx and travertine.
Siliceous stone, by contrast, is made mostly from silicates, minerals composed of the two most common elements in in the Earth's crust – oxygen and silicon. Unlike calcareous stones, you can use acidic solutions on siliceous stones, although they're also relatively simple to clean. As an added bonus, they also tend to be long-lasting.
Some common kinds of siliceous stone include sandstone, granite and slate.
It's important to note that, despite the fact that siliceous stone is resistant to acidic liquids, it could contain traces of minerals that are vulnerable to acid. So what's the cleaning solution?
Namely, Dry-Treat's HANAFINN Oxy-Klenza™. This powerful alkaline cleaner can carry out heavy duty cleaning to eliminate stains on any stone surface, regardless of its chemical composition.