Coatings for gemstones

Abstract

The invention provides a decorative object comprising a transparent or translucent substrate having a body and at least one surface bearing a thin film coating. The coating imparts in the substrate a body color that appears substantially constant at different angles of observation. This body color is imparted in the substrate at least in part by absorption of visible radiation that is transmitted through said coating. The coating includes a high absorption layer comprising film that is highly absorptive of visible radiation. Also provided are methods of coating gems and other decorative objects, as well as methods of heat treating coated gems and other decorative objects.

1 . A gemstone having a body with a pavilion bearing a coating that serves as an absorber of certain visible radiation frequencies to provide color so as to impart in the gemstone a desired uniform body color that does not substantially change in hue when viewed at different angles of observation, said coating being born only on the pavilion of the gemstone, said coating including a high absorption layer of film that is highly absorptive of visible radiation such that the desired uniform body color is imparted in the gemstone.