Calcium magnesium carbonate, or CaMg(CO3)2, makes up the carbonate mineral known as dolomite. It is a typical sedimentary material that forms large beds that are several hundred feet thick. Dolomite is utilized as a source of magnesium oxide, a beautiful stone, and a concrete aggregate. Dolomite is sometimes used as a flux for the smelting of iron and steel in places where calcite limestone is rare or too expensive. The manufacture of float glass involves the use of a significant amount of processed dolomite. Dolomite and dolomitic limestone are added to soils and soilless potting mixes in gardening to reduce their acidity and as a source of magnesium. Common uses of this are in-home and container gardening.