Factors in choosing engagement ring are broken down into four groups, know as the Four Cs. They determine the quality and worth of diamonds.
There are old time diamond merchants and jewelers who believe they can accurately tell ideal cut diamonds size and quality with only a loupe, but we have found that they are often wildly off in their estimates.
ideal cut diamonds that is free from natural inclusions - trace minerals or other tiny characteristics - is the most sought after and there the most expensive.