Calcium carbonate

الوصف

Calcium carbonate, or CaCO3, comprises more than 4% of the earths crust and is found in Baluchistan pravince Pakistan.  Its most common natural forms are chalk, limestone, and marble, Calcium carbonate is one of the most useful and versatile materials known to man.
                                                       
Calcium carbonate, as it is used for industrial purposes, is extracted by mining or quarrying.  Pure calcium carbonate can be produced from marble, or it can be prepared by passing carbon dioxide into a solution of calcium hydroxide.  In the later case calcium carbonate is derived from the mixture, forming a grade of product called "precipitated calcium carbonate,.
                 
Calcium carbonate causes a unique reaction with acids.  Upon contact with an acid - no matter the strength - it produces carbon dioxide.
Usually white but also colorless, gray, red, green, blue, and yellow, brown, orange