Before you start looking at engagement rings, we suggest you find someone to engage. Otherwise, this could be a very sad process.
The Four C's
Diamonds are sold based on four characteristics, called the "Four C's."
Clarity refers to the flaws, or inclusions, in the diamond. The naked eye cannot pick up any flaws until you drop to SI2 on the scale.
Color is labeled from D to Z. Diamonds appear more "yellow" as you move down the scale. At G-H-I, it is still difficult to notice any color when a diamond is mounted.
Cut refers to the angles and proportions of a diamond. Some popular shapes are brilliant (round), emerald (rectangular), princess (square), and pear shaped.
The weight of a diamond. For a brilliant cut, a .5 carat diamond is roughly 5.3mm across.
(Some might say there's a fifth C that determines a ring's value: "Can it make her friends jealous?")
If you're looking for good value, consider a diamond with SI1 clarity and I color, since the flaws and color are not noticeable to the naked eye. If your girlfriend shops with a microscope, you might want to reconsider.
Get a certificate when buying your diamond (most jewelers will give this to you with your purchase). This prevents you from getting ripped off and provides you with all the vital data about your diamond. GIA is the leader in certifying diamonds.
Bert decided to propose to his girlfriend (or rather, the girl who least resented his affections) but didn't want to spend too much money on the ring. His pal Ernie claimed to have a supply of affordable diamond rings with I48 clarity and triple-Z color. "I didn't think the scale went that low," Bert replied.
"Oh yeah, I've seen rocks much worse than those," Ernie assured him. "Mostly gravel."
Bert trusted his buddy and ended up giving his gal something that resembled a two-month-old corn nut. Her restraining order is still in effect.