limestone or calcium carbonate is a sedimentary rock, dominant organogen, white, gray or yellow. The rock is composed mainly of the minerals calcite and aragonite both with the chemical formula CaCO3. The minerals that can be present in very variable proportions are clays (metallic or non-metallic hydroxylates such as aluminum, magnesium, iron, calcium, potassium and sodium), dolomite (CaMg (CO3)2), quartz, plaster and more.

Limestone is a rock with many variants, referring not only to the process of their formation, but also to the characteristics of the rock, as appearance or use.

The most famous limestone quarry in our country is found in Albeşti, Arges county. The rock here is yellow with gray and reddish hues. Monumental and architectural works were executed from the limestones exploited in Albeşti, among which: Arges Monastery, Peles Castle, the Royal Palace (the current National Museum of Art in Bucharest), Bucharest Central Post Office (the current Museum of National History in Bucharest), Arch of Triumph, Palace of Parliament and others.

The term limestone is used in differentiated technical or scientific language. E.g, the compact solid rock will be called limestone, while the porous rock is called chalk, while in the construction industry limestone is used as quicklime or the variant with a porphyry structure is called marble although the geologically true marbles are metamorphic rocks.