Marbling. Real marble is beautiful, but can be too heavy or expensive to be practical. The many types of natural marble can, not only be imitated, but the artist has the additional option of creating fantasy marbles of any tone or color scheme to match your needs.
On an awning. Painted bevel.
On Plexiglas. With painted shadow.
A couple of fantasy marbles with some gold and copper leafs.
Dark purple marble, more subtle than shown here. On carved Gatorfoam.
Fantasy marble on wood, colors match the building.