Gemologists grade diamonds into dozens of categories. Although this helps professionals in the gem trade, the average consumer can find this information confusing. Young couples looking for their first diamond engagement set may find this especially troublesome. While they want to gather enough information to make an intelligent decision, all that data may overwhelm them.

To help consumers make informed decisions, I’ve divided this article into two parts. First, I’ll explain diamond rating and what qualities have the greatest impact on diamond grades. Once you understand that, I’ll then have recommendations to help you choose a diamond.

Diamond Rating: What Qualities Matter Most?

You’ve probably heard of the 4 Cs of diamond grading. I’ve ranked them below, in terms of importance when you choose a diamond.

  • Cut: The most important property.
  • Color: The second most important property.
  • Clarity: The third most important property, provided the grade is “SI” (Slightly Included) or better.
  • Carat: The least important property.

Now, we’ll go through the evaluation of each property.

The Cut

One of the hardest properties to judge, the cut is nevertheless the most important. Choosing a well-cut diamond requires paying careful attention to a few key characteristics.…