or cinder. Material obtained through cooking a mixture of limestone and clay at a high temperature (approximately 1200 /1450¯C), generally distinguished as artificial or natural, on the basis of the use of the mixture prepared artificially or of materials (marlstone) that already contain the necessary components in adequate proportions. It is a fundamental element in the production of various types of cement, obtained by mixing in pre-established proportions of clinker with other components and then crushing everything together to obtain a fine, homogeneous powder. See Portland Cement, Pozzolan Cement and Slag Cement.