Photos from the Smithsonian: A gemology Mecca!

It's no secret that I'm a Gemologist. As such, any chance I get to visit the Smithsonian National Museum of Natural History is a very happy time. Here's a few photos I took last time I went.

Diamond Color: A Rainbow of Choices

Diamond Color

The vast majority of diamonds mined are tinted yellow or brown.  It is very rare to find a colorless or near-colorless diamond and especially in a large size.  It easy to take diamond colors for granted when one can walk into a jewelry store and see case after case filled with glittering, white diamonds.  But diamonds are not limited to colorless, yellow, or brown; diamonds come in essentially every hue in the rainbow from blue to red to pink to green (the one diamond color not available naturally is vivid kelly green).  For this article, we will discuss diamonds within the normal color range.

Normal Color Range

Most diamonds are assigned a color grade based on the color scale developed by the Gemological Institute of America.  This scale pertains to diamonds in what's called the normal color range.  This scale ranges from completely colorless (D) to light yellow or brown (Z).  The human eye can differentiate between millions of hues, but humans have very poor color memory.  Therefore, GIA painstakingly assembled a set of master color comparison diamonds representing every color in the normal color range.  A trained grader places the loose diamond to be graded table down (face down) and compares its color with that of the master stones to determine the color grade.  Any standard gemological laboratory within a jewelry store should also have a set of master stones (either diamond or cubic zirconia), although not every grade will be represented.  It is important to note that although most diamonds have a tint of yellow or brown, the normal color range also applies to all other diamond hues that are not intense enough to fall into the fancy color scale.

Color Grade Ranges

  • D, E, and F - Colorless table-up and table-down
  • G, H, I, and J - Near colorless; usually appears colorless table-up when set
  • K, L, and M - Faint color; color visible table-up
  • N, O, P, Q, and R - Very light color
  • S, T, U, V, W, X, Y, and Z - Light color

Color and Diamond Value

The allure of a D-color diamond tempts almost every diamond buyer, but such a grade is unnecessary even if you do not want your diamond to show any color.  D-color diamonds command a premium for their extreme rarity.  In fact, all other factors being equal, the greatest difference in value is between the grades of D and E.  By definition, all diamonds graded D, E, and F are colorless.  Gemologists and diamond graders differentiate between these grades by assessing the diamond's tone, the lightness or darkness of the color.  Colorless and near-colorless diamonds will hold their value over time.  Below these ranges, the resaleability is limited.  This is why diamonds that appear to have a color below that of the J-grade are often sold without a diamond grading report or are graded by laboratories with less strict standards in color grading.

In order to maximize your diamond budget, I recommend purchasing diamonds in the I-grade or higher.

Jared W. Olen, Graduate Gemologist (GIA), Accredited Jewelry Professional (GIA), Certified Diamontologist (DCA)