Shannon Barbour of Walnut Creek, Calif., relates to the DeBeers ads that encourage successful, independent “women of the world to raise their right hands and make their own statements.”

She bought her right-hand ring – white gold with three flush diamonds – two years ago at a jewelry show in Milan for about $700, saying that she was a bit inspired by a “Sex and the City” episode in which character Carrie Bradshaw touted the trend.

“I’m at that age where I’m not getting married anytime soon. So I figured, ‘Why not?,”‘ Barbour said.

Last year, 4.5 million diamond right-hand rings were sold in the United States, a 10 percent increase, according to the Diamond Information Center. While many attribute the spike in popularity to an advertising campaign launched in 2003 linking the gem with independence, many women say they have been designing and purchasing their own diamond rings longer, and for reasons more diverse than the latest consumer trend.

And married women purchase right-hand rings as well, said Helena Krodel, spokeswoman for the Jewelry Information Center, a nonprofit trade association.

Krodel calls the right-hand rings timeless fashion items. And depending on quality and craftsmanship, they can cost less than a designer handbag. The average diamond right-hand ring sold in 2006 cost $1,153, according to the Diamond Information Center. But you can find them for less than $500, Krodel said.