D9L

Cement is made from limestone, calcium, silicon, iron, and aluminum, among other ingredients. This mixture is heated in large kilns to about 2,700°F (1,482°C) to form a product know as clinkers, which roughly resemble marbles. These are ground into a powder and gypsum is added, creating the gray flour like substance know as cement. When water is added to cement, it triggers a chemical process that allows it to harden.
Using cement we have a chance to realize sculptures much more easily than our forefather who had to shape rocks or marble using years of work with hammer and chisel.