Scagliola

Scagliola (from the Italian "scaglia", meaning "chips"), is an artificial way of imitating marble and other precious material. It is a decorative building material. 
Stucco columns, sculptures, and other architectural elements can be made by scagliola. It came into fashion in 17th-century Tuscany.
Scagliola is a composite substance made from selenite, glue and natural pigments, imitating marble and other hard stones. The material may be veined with colours and stuck on to a core, or patterns may be carved into a prepared scagliola matrix. The pattern is then then filled with the coloured, plaster-like composite. Then it is polished with flax oil for brightness, and wax for protection. The whole thing gives a richness of colour not easy to get in natural marbles.