The word cement has an interesting etymology of its own, dating back to Roman times. The Latin word cæmenta meant chips, specifically the hewn stone chips used together with mortar in rubble construction. The root verb cædere means to chop or slay, precisely where we get the “-cide” suffix from, referring to something “slain.” Nevertheless, the English word cement has come to mean the binder of the plaster, stucco, mortar or poured concrete rather than the ‘chips’ or aggregates it holds together.
What makes a cement “natural?” The natural designation indicates that the raw material—a type of limestone known as clayey marl—is simply mined and burnt with no further additions. Portland and other “artificial” cements, by contrast, are produced from a man-made mixture of pure limestone, silicates and clays that resemble the chemical composition of marls or vary from them in a controlled, reproducible manner.