• Giant limestone rock.limestone islands1 image by Pierrette Guertin from Fotolia.com
  
  Limestone is a rock. It is mostly made of calcium. The calcium was deposited by the remains of prehistoric marine animals. It is extremely porous and takes thousands of years to form. It is soft and most often contains fossils. The rich calcium content of the rock makes it a productive additive to soil. The chemical diversity of limestone allows the steel industry to use it to cleanse iron made in blast furnaces. It is also used in some foods to aid in human calcium levels.
  
  

Soil

• Limestone is added to soil used to grow vegetables to balance the pH level and encourage growth. Garden dirt often becomes barren of nutrients and acids it needs to successfully grow living plants. Apply limestone in a powdered form to restore fallow soil to one that is properly pH balanced. Place directly on the top soil and then water to begin the process. Monitor pH levels closely at this point to avoid overuse of limestone, which will result in wilting of the plant and roots.
  
  

Iron Skillets and Cooking Utensils

• Iron is used all over the home every day. Pots, pans, skillets and a variety of cooking utensils are made of iron. The pipes that carry water into homes and other structures are made with iron mixed with limestone as well. Steel industries produce molten iron by feeding coal and other compounds into a high-intensity heat furnace. Limestone is also added to help burn impurities, called slag, out of the iron. The chemical makeup of limestone causes the impurities in the metal to rise to the surface and then they are skimmed off. This iron is, in turn, used to produce household items such as pots, pans and cooking utensils.
  
  

Food and Food Products

• Flour is a large part of the American diet. Breads, cakes, gravies and myriad other dishes are made with flour. Limestone is added to flour to enrich the calcium level. Adding calcium in this fashion helps to deter bone diseases such as osteoporosis and rickets. Sugar is another product that is used every day. Limestone is added to sugar to help filter out natural impurities; it is also added to salt to make it easier to pour. Limestone is found in the poultry food farmers use to feed their laying chickens, which supply the eggs for grocery stores throughout the country. It is also used in pig feed to add nutrients to their diet.
  
  

Dishes and Ceramics

• Many dishes and other ceramics have limestone mixed in them to add stability. The limestone is mixed with the clay and other compounds to make the dishes stronger and less likely to chip. Limestone dishes and ceramics have several decorative uses as well. Limestone is also used to make glasses. Mix and heat limestone with other chemical compounds and it forms clear, hard glass used in drinking glasses and dishes.