By Åse Anderson in London
Extravagant and beautiful, the rarity of pink diamond engagement rings only makes them more covetable.
Natural pink diamonds are very scarce and expensive: one carat of a pink diamond can be worth between 20 to 40 times as much as a carat of an equivalent white diamond. And don't expect prices to come down any time soon: the Argyle Mine in Western Australia that produces over 90% of the world's supply of pink diamonds is set to close within the next four years.
Even now, in an average year only 65 pink diamonds will be found at the Argyle Mine, representing 60.00 carats of its total production. These rare gems then embark on a worldwide tour to cities such as London, Hong Kong, Tokyo and Sydney where a small number of bidders are invited to make sealed bids for the stones. For security reasons the tour is so shrouded in secrecy that the exact locations are kept under wraps until the very last minute. Prices vary according to the size, colour and clarity of each diamond but will range from tens of thousands per carat to over a million dollars a carat.
Read more on Argyle pink diamonds
Given this complicated process and nature's dwindling supply, natural pink diamond engagement rings are not easy to come by and, unless you are in the realm of the super rich, may require a second mortgage.
The pink diamond engagement ring that Ben Affleck gave to Jennifer Lopez back in 2002 regularly pops up in articles of the most expensive celebrity engagement rings. Worth a cool $1.2 million and weighing in at 6.10 carats, Lopez reportedly returned the Harry Winston ring when the couple split in 2004.
Read about the record-breaking Unique Pink diamond
Similarly, tennis player Anna Kournikova's natural pink diamond engagement ring, with a pear-cut centre stone from the Argyle Mine, has an estimated value of $2.5-6 million.
If you love the look of a pink diamond but your budget doesn't stretch to the real thing, a pink sapphire centre stone will give you the same look at a fraction of the price. In this Anne Sportun engagement ring from Astley Clarke, the pink sapphire centre stone is set in gold and surrounded by a circle of channel-set white diamonds.
Alternatively, if you are set on having natural pink diamonds, you can opt for an engagement ring with smaller pink diamond side stones, such as this Tiffany & Co. pink diamond engagement ring. It features a round brilliant white diamond elegantly framed by six Fancy Pink diamonds, weighing a total of 0.03ct.
With the source of pink diamonds rapidly depleting, if you can afford it, now is the time to invest in pink diamond engagement rings as their value is only likely to increase in years to come.
Read more about the history of pink diamonds
Calleija oval-cut pink diamond engagement ring featuring a pink diamond central stone surrounded by white diamonds.
Messika Heart pink diamond engagement ring with rose gold prongs and a diamond pavé band.
Jessica Poole Twist pink diamond engagement ring set with a natural pink diamond and pavé white diamonds (from £2,400).
Tiffany & Co. pink diamond engagement ring featuring a round brilliant white diamond elegantly framed by six Fancy Pink diamonds.
Calleija Elyssa pink diamond engagement ring featuring a brilliant-cut Fancy Intense Purplish Pink diamond centre surrounded by pink and white diamonds.
Boodles marquise-cut pink diamond engagement ring surrounded by a double pavé of white diamonds leading to a double pavé band.
Graff emerald-cut pink diamond engagement ring with a diamond band.