Brett Fahlgren: I was the first to pop a question amongst my group of friends and now it is friends who are firing questions away at me. As the GQ style correspondent I'm used to getting advice and the moment you decide to propose to your girl friend is about as intense as you can get. You pick the women that you want to spend the rest of your life with and now you got to create a moment that sure remember for the rest of hers. You'll struggle on picking the place, the time, your tie but the most important choice you'll make is the ring.

Now, don’t worry you don’t need to pick a ring everyday and no one expects you to be a diamond expert. So we’re going to give you some short cuts. The one phrase to remember is the four C’s. Let's talk to the man on the street about what he knows about the four C’s and there is no better place for that than here in Time Square.

What do you know about diamonds?

Male: That my mom likes them.

Male: First, to get out on a budget, a couple months salaries from my understanding.

Male: I know that they last forever but their hard, expensive.

Brett Fahlgren: What do you know about the four C’s?

Male: I know absolutely nothing about the four C’s.

Brett Fahlgren: Do you know anything about four C’s.

Male: No.

Male: I probably used to remember but I can't remember that now.

Brett Fahlgren: Carat, cut, clarity is one, and there you go.

Male: Carat.

Brett Fahlgren: Say more.

Male: Color, composition.

Brett Fahlgren: Composition that was clarity.

Male: Cost.

Brett Fahlgren: No, so let's try our confusion into curiosity and go straight to the source. Meet John King of Gemological Institute of America. John is going to clarify some misconceptions and let us know what to look for when buying a diamond. Tell us what goes into assessing a diamond’s value.

John King: Well it’s actually is more than size in assessing a diamond’s value. It’s really made up with the four C’s color, clarity, cut, carat. Carat refers to the weight of the diamond. A carat is made up with 100 points. It’s top the weight of a couple grams. Think of holding a paper clip. Larger weights diamond those with more carats and more valuable because they're rarer.

Brett Fahlgren: Tell us about clarity.

John King: Clarity, it’s referring to the relative absence of inclusions in the stone. The cut refers to how wide the diamond has been proportioned and what the facets have been in place on it, how well they’ve been polished.

Brett Fahlgren: Finally color.

John King: The diamond’s people in common most frequently, it first appeared to show no color at all, in truth there is very subtle, tense of color, most often yellow and brown. The more colorless the diamond the rarer it is and therefore the more valuable.

Brett Fahlgren: For John King of the GIA, I'm Brett Fahlgren from GQ.