Champagne Diamond from Argyle Mine, Australia. Champagne, cognac and chocolate diamonds have been heavily marketed since it was discovered that Argyle mine has mostly brown diamonds, which were previously only used for industrial purposes. It's estimated there are a trillion carats of diamonds yet to be mined there.
The Orangy Brown, or Orange Brown diamonds have such a striking resemblance to the golden shade that this combination of colors actually adopted the Golden Diamond name. Description from leibish.com. I searched for this on bing.com/images