Gypsum, Limestone, and Soil

Gypsum when heated to 150 °C becomes calcium sulfate hemihydrate,
Then this material is called "Plaster of Paris", and when mixed with water it reforms into Gypsum.

Limestone(A.K.A. Calcium carbonate)when heated to 825°C becomes calcium oxide(A.K.A. Burnt lime, or Quick lime) this new material is called cement, and when mixed with water and carbon dioxide turns back into calcium carbonate, or limestone.

Soil is composed of Sand, Silt, and Clay. Sand is the largest sized particle contained in soil, Silt is the second largest sized particle contained in soil, and clay is the smallest sized particle contained in soil. Clay and Sand when mixed together with water in a ratio of about 30% clay and 70% sand, and are allowed to dry are now known as the material "Stucco".

When these 3 materials are mixed together along with clay minerals you now have what is call "Portland Cement" which is comprised of ( concrete, mortar, stucco ) and add water this new mix is stronger than the previous individual materials by themselves. But there is a special technique to producing Portland cement, and a special ratio of each component substance.