Venetian plaster is really a general term that refers to putty made from fired limestone combined with water. It’s then mixed together to make lime plaster. (So Venetian plaster and lime plaster are the same thing.) And when that lime plaster is applied to walls and exposed to the carbon dioxide in the air, the mixture turns back into limestone. So it starts as limestone and ends as limestone—truly magical! And it's the same stuff our ancestors used in ancient Greece and Egypt. Incredibly, it has endured the test of time, both physically and aesthetically.
When applied correctly, Venetian plaster can be used to create a highly polished, rock-hard, marble-like finish. Venetian plaster is especially useful on surfaces where marble panels could not be installed easily, and on surfaces that would be too expensive to have carved from real marble such as columns, corbels, and curved walls.
Venetian plaster can be tinted, or colored using natural or synthetic colorants. The ability to tint Venetian plaster is especially helpful when a specific color of "marble" is desired, or when a color that does not exist naturally is wanted.