March 2, 2010
Natural Pink Diamonds
Pink diamonds are rare. Natural pink diamonds are even more rare. In fact, most jewelers will not see a natural pink during their years in the jewelry industry.
According to the February 2010 edition of Jewelry Insurance Issues, a monthly newsletter for jewelry insurance professionals, pink diamonds are pink because of their structure and a process known as “plastic deformation.” Many other fancy-colored diamonds get their color from impurities embedded in the gem material. However, in pinks, intense pressure changes the lattice structure of the diamond while the crystal is growing. This produces the visual spectrum of pinks from bubble gum to raspberry.
Gemological Institute of America (GIA) laboratories grade hundreds of thousands of diamonds every year and of those diamonds only 5 percent are strongly saturated colors called fancies. The JII article states of that 5 percent, only a tiny fraction are classified as pink.
The article also indicates that nearly all of these high-value pink diamonds come from the Argyle diamond mine in Australia. The very best pink diamonds are offered each year in an exclusive sale known as the Argyle Pink Diamond Tender. 
“For every million carats of rough pink diamonds produced by the mine, only one carat is of high enough quality to be offered for sale at the tender.”
The rarity of pink diamonds makes them extremely expensive. For example, a 5-carat pink diamond set world auction records in December 2009 by selling for $2.1 million per carat!
