A pure natural fancy orange diamond is extremely rare in nature.
The orange color of an Orange diamond is a combination of yellow and red. Usually orange diamonds can be found in combination with yellow or brown, and even then it's usually the secondary color.
To understand the difference between orange diamond and orangy, one should consider the way that the labaratory grades the diamonds. According to labs when the orange color within the stone is 25%-50% it's called an orange diamond and when it's 25% or less it graded as orangy.
Like with other colored diamonds, the intensity of the orange diamond varies from fancy light orange to fancy orange diamond and goes up to the desired, rare (and expensive) fancy intense orange diamond, fancy deep orange diamond and the beautiful fancy vivid orange diamond.
Colored Diamonds is a very small niche within the beautiful world of natural diamonds. When we talk about rare diamonds we often talk about natural colored diamonds. It is said that less than 0.01% of mined diamonds are natural colored diamonds. But it is importand to understand that only a very small fragment of these are natural orange diamonds.
Amongst the amazing orange diamonds color combinations you can find the sought after pumpkin diamond. The pumpkin diamond is actually a nick name to a combination such as yellow orange or yellowish orange. The truly amazing pumpkin diamonds are those with vivid intensity. These rare pieces are very hard to find and hence their prices. Keep in mind that in the GIA certificate the color description of these diamonds would be Vivid Yellow Orange and not pumpkin. In the video below you see a great sample of a vivid yellowish orange diamond with I2 clarity. It has such a brilliance that it completely hides the inclusions making it "eye clean". This specific 1.50 carat orange diamond costs about $10,000.
There are many famous orange diamonds but the most famous orange diamond (and most famous orange diamond ring) is The Pumpkin Diamond. The Pumpkin is a 5.54 carats vivid orange diamond - a truly rare exhibit. It was purchased in auction at Sotheby's by Ronald Winston for the price of $1.3 million. A ring mounted with the Pumpkin Diamond was designed by Ronald Winston and Phillip Bloch, and worn by Halle Berry at the 2002 Academy awards where she won best actress. The diamond is now valued for over $3 million.