This is The Canary Diamond which is a Yellow Diamond but it is one of the most beautiful Yellow Diamonds in the world as it is of a different kind than any other diamond.
The Canary Diamond unlike the others is Fancy Deep color. When a cutter cuts a mined Yellow Diamond he must find the best cut for it because the cut will make the radiance up to 50% more brilliant. Yellow Diamonds are the same price as regular clear diamonds.
More on Yellow Diamonds at my blog.
