METHOD OF COLORING FIANITES Russian patent published in 2007 - IPC C30B33/02 C30B31/02 C30B29/16 C30B29/22 A44C17/00 

FIELD: jewelry industry; optics.

SUBSTANCE: proposed method is used for coloring fianites (man-made diamonds) in green, blue and brownish-yellow colors; proposed method may be also used in optics for production of colored light filters withstanding temperatures above 1000°C. Proposed method includes preliminary application of cobalt on fianite surface to be colored and at least one metal whose oxide is liable to spinelle-forming with oxide of bivalent cobalt, iron and/or aluminum, for example. Then material is subjected to heat treatment in oxygen-containing atmosphere at temperature above 1000°C but not exceeding the fianite melting point. The procedure is continued for no less than 3 h. Coat is applied by thermal spraying of metals in vacuum. Said metals may be applied in turn and simultaneously. For obtaining bluish-green color of fianite, cobalt and aluminum are applied at atomic ratio of 1:1 to 1:2. For obtaining yellowish-green color, cobalt, aluminum and iron are applied at atomic ratio of 1:1 :0.1-0.2. For obtaining yellowish-brown color, cobalt and iron are applied at ratio of 1:1 to 1:2.

EFFECT: enhanced resistance to high temperature and chemical action.

7 cl, 11 ex