And finding three matching blue diamonds? Well, that's nigh to impossible, and even then the resulting ring would require a king's ransom to own. That's why we decided to offer this best-of-all-worlds alternative: a just-over 1/2 carat, color-enhanced center blue diamond showcased between two .28 carat white diamonds (G-H color, I1 clarity). Designed in a classic prong setting on 18K white gold, this combination not only makes a refreshing change from an 'ordinary' 3-stone diamond ring but also has the advantage of making that extraordinary robin's-egg blue dazzle really 'pop!' Yet it's still timeless enough to present as an engagement ring or an anniversary gift or even as a symbol of your true-blue loyalty and fidelity. What's more, she has the satisfaction of owning-and perhaps uncharacteristically for her, even flaunting!-a ring that's as one of a kind as she is. Available in sizes 5-10.