Red diamonds are known to be the rarest of rare
Red diamonds are the most rare of all colours, and as such sit at the very top of the value scale. They represent one of the most sought after hues in any fancy colour diamond collection, mainly because they are so rarely available.
Prices for red diamonds start at seven figures per carat. The prices of red diamonds are hard to compare since there are dramatic differences between them – even with the same certificate, two purplish red diamonds can be in completely different price levels – based on how red the diamond is, how bright or dark the tone, and the amount of any secondary colours present.
Red diamonds with no secondary hue are so rare, that GIA records show that over a 30 year period from 1957 to 1987 there was no mention of a GIA lab report issued for a diamond with ‘red’ as the only descriptive term. In addition, there have been less than 400 diamonds that have been graded by GIA weighing more than half a carat.
Hue is the dominant colour of the diamond; saturation is the strength of hue; tone is the amount of light or darkness in the diamond.
The Hancock Red is one of the most famous red diamonds. At the time of its sale in 1987 it was the most expensive per-carat gemstone ever sold at auction. The hammer came down at $ 880 000 a remarkable $ 926 315 per carat, eight times its pre-sale estimate. The publicity generated by the selling price of the Hancock Red and other significant fancy coloured diamonds at auction spurred interest in these rare stones around the world at the time.
It Is important to note that fancy reds do not have a saturation level (for example ‘intense’ or ‘vivid’), as they represent the greatest level of colour in the pink diamond family – there is no greater saturation possible. In addition, they do not get very large in size, with the 5.11 carat Moussiaf Red shield being the largest known red diamond in history.
One of the many attributes we consider when we grade and evaluate a diamond that are outside the 4Cs is fluorescence. Most people know that fluorescence is considered a flaw and reduces diamond prices. This is true in white diamonds but not exactly true in coloured diamonds with the exception of yellow diamonds. Unlike in other coloured diamonds, fluorescence does reduce the value of yellow diamonds, even dramatically.
Pure things such as diamonds with no fluorescence are rarer and therefore cost more. Secondly, fluorescence in yellow diamonds is usually blue. If you look at a yellow diamond with strong blue fluorescence it does seem to affect the colour but not always.
Faint fluorescence reduces the price a bit (up to 10%), Medium or Strong reduces a lot (even 15% - 30%).
While Pink and blue diamonds were unaffected over the GFC, yellow diamonds suffered a 45% decline in value between January 2008 and January 2009 as most retail consumers lowered their spending and demand plummeted and supply remained steady.
However, the following year, yellow diamonds increased 52% in value and continued to increase in value to fully recover their pre-recession value by January 2012. They continue to perform consistently, and have outperformed many traditional investments, particularly in the top Vivid Yellow category.