Anna Wallner and Kristina Matisic RELATED LINKS Watch The Shopping Bags on FINE LIVING About the Shopping Bags: Anna Wallner and Kristina Matisic VIDEO TIPS: The Shopping Bags give quick pointers on more than 100 items

By Anna Wallner & Kristina Matisic

Valentines Day is just weeks away and if you're thinking of popping the question on February 14, it might be time to go diamond shopping. But this is a big purchase so obviously worth a little research before you hit the mall. Keep the following tips in mind when buying diamonds:

• First and foremost, buy the stone, not the ring. Buying an unset stone will allow you to verify color, clarity and proportions in a way that simply can't be done when a stone is in a setting. The yellow or white metal color of the setting will affect the color and appearance of the stone. And when parts of the diamond are covered with claws or a bezel, flaws may be hidden from both you and the salesperson.

• Know the four Cs of diamond shopping: cut, color, carat and clarity. Cut refers to the way a diamond reflects light — its sparkle — and to the shape of the diamond. Color, is just that. Diamonds range from absolutely colorless, and very expensive, to yellow or pink. (Which can also be expensive!) Clarity is the flaws that every diamond has. From very, very slight flaws that you can barely see, even under a microscope, to larger blemishes that are visible to the naked eye. And finally carat; it's the weight of a diamond, and it's really tiny. A 1-carat diamond only weighs 200 milligrams, or two tenths of a gram.

• If there's a gemologist on site — they tend to be found at high-end specialty jewelers — the store will have a microscope. Ask to use it to inspect any stone you're considering. The microscope will allow you to see flaws, color and characteristics of the stone.

• If you're purchasing a stone that's half a carat or larger, make sure the stone has been certified. Not all certifications are created equal, however. Our experts recommend certifications from the Gemological Institute of America, the American Gem Society or the Diamond High Council in Belgium.

• Have the stone you're considering examined by an independent, certified appraiser (who doesn't work for the store).

• To ensure a diamond is real, hold the stone above a newspaper. If you can read the newsprint, it's a fake!