We probably have the "Bennifer" factor to thank for the resurgence of popularity in pink diamond rings in recent years.

The 6.1 carat pink diamond ring that Ben Affleck presented to Jennifer Lopez on their engagement sparked so much interest that colored diamond specialists everywhere clapped their hands with joy.

"We haven't seen this much interest in pink colored diamonds for the 70 years we've been in operation," said Mervyn Seigelman, from Seigelman & Sons, a well-known New York based diamond merchant. "Pink diamond rings are so popular we are unable to meet the demand."

Colored diamonds, often referred to as "fancy" diamonds, are more rare and therefore more pricey than their whiter counterparts, with pink diamonds the most rare of all the fancy colored diamonds.

Where a colorless diamond may set you back around $5,000 to $10,000 per carat, a natural pink diamond retails for anywhere between $10,000 and $400,000 per carat.

While the more traditional white diamonds are graded on a number of factors, including cut and clarity, colored diamonds are judged primarily on the purity of their color. Pink diamonds can range in color from deep magenta through to barely-there pale pink.

The Argyle diamond mine in Australia now produces over 90% of the world's pink diamonds, and are renowned for the quality of all their colored stones. Argyle pink diamonds have wonderful depth and intensity of color in their mined pink diamonds.

Fancy colored diamonds can also be produced in laboratories. Natural colorless stones are treated to produce a multitude of colors, from blue, yellow and green to pink, red and even black diamonds. Of course, a natural pink diamond is more valuable than a lab-created diamond, but only an expert can usually tell the difference.

If you have your heart set on a pink diamond engagement ring, you may have to do a little searching as they are not generally carried in most jewelry stores. Gemstones like pink sapphire, tourmaline and spinel can be alternatives if your budget doesn't stretch to a pink diamond, but nothing matches the radiance, fire and durability of a diamond.

And for those who want the bling without the big bucks, colored cubic zirconia may be just the thing. In fact, a copy of J. Lo's pink diamond engagement ring featured here and available from emitations.com is one of their biggest sellers.