Some tips to keep in mind before you buy that diamond ring

With Valentine’s Day approaching, plenty of guys will be popping the question. And if you’ll need a diamond to go along with that proposal, now is the time to buy.

While prices vary widely based on the quality of the cut and the rarity of the stone, diamond costs in general remain about 10 percent below their levels of a year ago.

But those prices have started to creep up from their lows in March and the relative bargains won’t last long as the effects of the recession wear off and an oversupply of polished gems diminishes, retail diamond sellers say.

“This is a very good time to buy diamonds,” says Dione Kenyon, president of the Jewelers Board of Trade, an industry credit bureau. “There is a fair amount of inventory still out there because of the weak demand and because of a general aversion to wearing bling during these economic times.”

But don’t be blinded by love when diamond shopping. The process can be intimidating because of the lofty prices involved and what to the untrained eye can appear to be minor distinctions between stones. Markups on retail sales can be anywhere from 50 percent to 100 percent, jewelers say.

When Callum Streeter began shopping for a diamond for his fiancee’s engagement ring a year ago, he did what most first-time diamond buyers do: he researched pricing, the four C’s of diamond classification — color, cut, clarity and carat weight — and set a budget. He searched online and looked at stones at a number of stores.

But the one thing Streeter did that wasn’t conventional: He purchased his diamond online, from Blue Nile, the largest online seller of certified diamonds.

The 26-year-old Streeter figures he saved $8,000 to $9,000 on the more than $20,000, 2.06-carat round ideal-cut rock he is having set for his bride-to-be.

Most traditional jewelers such as Tiffany, Jared or Zales that buy diamonds from large manufacturers and display them under glass in a retail store will also showcase stones and settings online and send rings to local stores for pick up.

“Customers should shop around and buy from reputable jewelers with an experienced and educated staff, with certified diamontologists (who) can explain the different qualities of the diamonds available,” said David Bouffard, spokesman for Signet Jewelers, parent of the Jared and Kay retail chains.

There are plenty of independent sources online to learn about diamonds and most major diamond sellers will have tutorials on their sites that explain what to look for when buying diamonds and how to balance clarity and cut, for example, with carat size and color.

“It’s not rocket science,” said Blue Nile’s Chief Executive Diane Irvine. “With a little research anyone can buy diamonds just like a professional jeweler would buy them.”