Step 4: Gem Grading

Lesson 14


Diamonds come in every color of the rainbow. Our standard white diamonds are either colorless or tinted slightly yellow. We gemologists consider all other colors “fancy colors.” Fancy colored diamonds occur at an estimated rate of one to two carats for every three thousand carats mined. Due to this rarity, these fancy diamonds demand higher prices than white ones.

We can’t grade fancy colored diamonds by white diamond grading standards. In 1994, the Gemological Institute of America (GIA) refined their standards for fancy colored diamonds to meet current demands. This is the most commonly used system. Once you understand it, it’s very clear.

Inform Your Customers About Diamond Colors and Heat

First, some advice. Please tell your customers that some diamonds, particularly green ones, may change color if heated by a jeweler’s torch. This applies to both natural and artificially irradiated diamonds. Since this color change is permanent, recommend they ask jewelers to remove mounted colored diamonds before making jewelry repairs.

Distinguishing Natural from Enhanced Diamond Colors

Approximately one third of all colored diamonds have artificially induced colors. Typically, determining if the color is natural or artificial falls outside…