Black gold

Black gold is a type of gold used in jewelry. It is created by various methods, such as electrodeposition using black rhodium or ruthenium; plasma assisted chemical vapour deposition process concerning amorphous carbon; and controlled oxidation of carat gold containing chromium or cobalt. Electroplating solutions that have ruthenium give a slightly harder black coating than those that contain rhodium.

Unfortunately, black gold is very hard and making jewellery out if it regularly necessitates using previously-made melting forms. Varying the size, adding stones or other customizations are often too hard for the common goldsmith.