Yes, orange diamonds are real diamonds. Like other coloured diamonds, they are formed naturally within the Earth's mantle under high pressure and temperature conditions. The orange colour of these diamonds is caused by the presence of nitrogen in the diamond's crystal lattice structure during formation. The amount and arrangement of nitrogen atoms influence the specific shade and intensity of the orange colour in the diamond. Natural orange diamonds are relatively rare, and those with a deep, vivid colour can command premium prices. Their unique and captivating colour properties make them popular among collectors and diamond enthusiasts.

Natural orange diamonds can come in a range of shades and intensities, from pale orange-yellow to deep, vivid orange hues. The GIA colour grading scale for orange diamonds ranges from Fancy Light Orange to Fancy Deep Orange.

Orange diamonds can also have secondary hues or modifiers, which can affect the perceived colour of the stone. For example, an orange diamond with a pinkish modifier will appear differently from one with a brownish modifier. The exact shade of orange and the presence of any modifiers can influence the value and rarity of the diamond.

The Pumpkin Diamond is a rare and famous natural diamond weighing 5.54 carats, with a fancy vivid orange colour, and rated as internally flawless. It was discovered in Central African Republic's premier mine in the late 1990s and later acquired by Ronald Winston of Harry Winston Inc. The diamond was named "The Pumpkin" due to its distinctive orange colour and was later showcased in several public exhibitions, including the Smithsonian National Museum of Natural History. The diamond's unique colour, excellent clarity, and impressive size make it one of the world's most renowned and valuable coloured diamonds.