Expand is a combination of the Latin words ex-, meaning out, and pandere, to spread. The idea of spreading out was always there, though the current idea of something actually becoming larger was first recorded in the mid-17th century.
Aragonite and calcite are two minerals formed from calcium carbonate (CaCO. Lime (calcium oxide) is produced by heating limestone or seashells (calcium carbonate). The chemistry of calcium carbonate is similar to that of sodium carbonate and potassium carbonate except that calcium carbonate is not soluble in water.
Calcium Carbonate. The chemical compound calcium carbonate is composed of calcium, carbon and oxygen. A simplified equation for its formation would be the addition of calcium, oxygen and carbon dioxide to form CaCO3, the chemical formula for calcium carbonate. A major source of the compound is marine organisms such as coral, shellfish and mollusks, which use it to construct their shells, or skeleton-like casing.