It all began in 1477 when Archduke Maximilian of Austria gave Mary of Burgundy a gold ring set with a diamond as a token of his love.

Today, the tradition of the diamond engagement ring is still going strong.

Approximately 75 percent of the 2.5 million couples who become engaged each year give or receive a diamond as a symbol of their commitment, according to the Diamond Information Center.

Starry-eyed couples call an engagement or wedding diamond an investment in the future and an investment in their love.

Anyone who has ever purchased a diamond knows that it's also a sizeable financial investment and that it takes some education to find the best value.

Following are some tips for those in the market for a rock that is large, small or somewhere in between:

HOW MUCH?
Deciding how much to spend on a ring doesn't require any heavy-duty calculating. Just use two months' salary as a spending guideline and choose the finest quality diamond in the bracket, suggests the DIC.

THE FOUR "Cs."
When shopping for the diamond of your dreams, remember that there are four variables that determine the quality of a diamond: clarity, color, carat weight and cut, says the DIC.

A diamond's clarity, for instance, is determined by the degree to which it is free from inclusions, while its color is measured by the degree to which it approaches colorlessness.

Carat refers to the weight of the diamond, and a quality cut is what gives a diamond its brilliant sparkle.

SUPER SETTINGS
From channels and clusters to paves and solitaires, settings provide a world of options for the most beloved of precious stones.

Whether traditional and timeless or sleek and contemporary, today's settings are designed to put diamonds in their best possible light.

OTHER OPTIONS
While the diamond wins hands down as the most traditional and popular choice, it certainly isn't the only option.

Some couples, for instance, choose a classic or contemporary band ring in 14-karat,18-karat gold or platinum.

Those with a penchant for something old have antique heirloom rings resized in honor of their impending nuptials, while others create something new by designing their own rings with the help of a custom jeweler.

Gemstones, such as rubies, aquamarines or sapphires, present still another jewelry box of options.