Orange diamonds are not as rare as the red or green diamonds. Most of the orange diamonds have strong yellow or brown modifiers. Pastel coloured orange diamonds are of similar value as pastel pinks & some blues. To be classified as orange, there must be a complete absence of brown to the stone. This colour of orange is called “apricot.” It is unknown what causes this colouration. There are so few actual oranges, especially ones of known mine origin, that it is difficult to study.
Orange diamonds that look like a Halloween pumpkin sell for more than the yellows. An 8.93 fancy intense orange sold for about $1.9 million at Sotheby’s. Oranges with yellowish secondary colours and with just a hint of brown have lower prices.
Common names for orange diamonds include amber, autumn, peach, burnt orange, cognac etc. Orange diamond rough is mined in Australia and South Africa. Orange colour occurs due to unknown structural defects in the diamond. The secondary hues and colour modifiers for orange diamonds include yellow, pink, red, brown etc.
Enhanced orange colours mimic the natural ones so well that they are difficult to detect. Again, price factor is the main reason we see so many of the enhanced orange colours on the market.