If you have to buy, receive, or otherwise play a part in the diamond purchasing process, you have to pick the right diamond. The recipient will likely own the diamond for decades and the resale value of engagement rings, frankly, sucks. Therefore, it’s pretty important to pick the right one. Know the 6 Cs of diamonds (Yes, 6. You read it here first, folks.): carat, color, cut, clarity, certification, and cost. Know what’s most important to the recipient and what she would sacrifice in order to get a bigger (clearer, etc.) stone. Would she be happy with a smaller stone if it had no inclusions? Would she accept a slightly yellow stone if it meant it would be bigger?