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,^[1] 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,^[2] 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.

1. ↑ Stucco is a material used for decoration in buildings. It is made of an aggregate (such as sand) plus a binder (such as lime) plus water. Animal or plant fibres are often added to give it strength. Modern stucco might add acrylics and glass fibres to make it last longer.
2. ↑ Selenite is a crystalline form of gypsum, and gypsum is basically a form of calcium sulphate (CaSO₄·2H₂O)