Calcium carbonate, also called calcite, is the main component of limestone. magnesium carbonate, also called magnesite, is the main component of chalk used as a drying agent for hands in rock climbing, gymnastics and weight lifting. potassium carbonate is also called potash. zinc carbonate is sometimes referred to as zinc spar or smithsonite. Trade name: magnesium carbonate cas 12125-28-9 es (einecs) 235-192-7 synonyms : magnesium carbonate hydroxide, magnesium carbonate basic 1.2. relevant identified uses of the substance or mixture and uses advised against magnesium for athletes, for example: climbing. 1.3. details of the supplier of the safety data sheet Gibson athletic premium block gym chalk, 1lb, consists of (8) 2 oz blocks, magnesium carbonate, gymnastics, weightlifting, rock climbing white. 4.6 out of 5 stars 178. $13.99 $ 13. 99. get it as soon as thu, sep 26. free shipping on orders over $25 shipped by amazon. amazon's choice for magnesium carbonate. Magnesium carbonate is odorless white powder. it has the melting point of 350 degree celsius and all forms of magnesium carbonate reacts with acids. uses of magnesium carbonate. the primary use of it is in the magnesium oxide production through calcining process. magnesium carbonate is used for flooring, fireproofing, in cosmetics and toothpaste.