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.
The calcium carbonate content of limestone gives it a property that is often used in rock identification - it effervesces in contact with a cold solution of 5% hydrochloric acid. Chalk: A fine-grained, light-colored limestone formed from the calcium carbonate skeletal remains of tiny marine organisms.