What to Look for When Buying a Modern Round Diamond
For new round diamonds buy a diamond with a GIA lab report. GIA is the Gemological Institute of America and they are the world’s foremost authority in gems and gemology.
What you want to do is to buy a Modern Round Brilliant Cut diamond with a GIA lab report that has a Good Cut Grade, Very Good Cut Grade, or better still an Excellent Cut Grade, (it’s a proportion score). The cut grade of a diamond can be 40% of its value. A diamond with a cut grade of Good, Very Good or Excellent will be full of sparkle. With a GIA cut grade you don’t have to worry with any of the other details like crown angles, depth, table size, etc. Note: GIA lab reports before 2001 did not include a cut grade for round diamonds.
If you want the diamond to be very white stay between D and I color. For a diamond where you don’t see any flaws you will want the clarity grade to be between Flawless and Si1 (Slightly included 1). There are many gorgeous Si2 and I1 clarity diamonds with a GIA Very Good or Excellent Cut Grades so you should look at them also because they are so much less expensive.
A diamond with fluorescence is not a bad thing; actually it can be a good thing. When a diamond has fluorescence just make sure it is not stronger than medium, and no color other than blue.
