Diamond color

History and Grading of Diamond Color

• Color grading performed by London Diamond Syndicate
• Early grading systems lacked standard nomenclature and consistency
• Early grading scales included III and AAA
• Numerous terms developed to describe diamond colors
• Diamonds occur in a variety of colors due to impurities or defects
• Diamonds classified into Type I and Type II based on impurities and light absorption
• Type I diamonds have nitrogen impurities, resulting in yellow to brown tint
• Type II diamonds have no measurable nitrogen impurities and absorb in a different region of the infrared

Types of Diamonds and their Colors

• Type I diamonds have nitrogen atoms as the main impurity
• Type IaA diamonds have nitrogen atoms in pairs, no effect on color
• Type IaB diamonds have large even-numbered aggregates of nitrogen atoms, yellow to brown tint
• Type Ib diamonds have dispersed nitrogen atoms, intense yellow or brown tint
• Type II diamonds have no measurable nitrogen impurities, absorb in different region of infrared
• Type IIa diamonds can be colored pink, red, or brown due to structural anomalies
• Type IIb diamonds are usually light blue and contain scattered boron
• Green diamonds caused by GR1 color centers in crystal lattice due to radiation exposure

Color Grading of Diamonds

• Majority of mined diamonds fall between white and pale yellow or brown
• More intense color diamonds termed fancy color diamonds
• Colorless and vivid color diamonds are the most valuable
• Diamonds in the normal color range graded using a standardized scale
• Colored diamonds graded using separate systems
• Yellow or brown color diamonds more intense than Z considered fancy colored diamonds
• Grading of colored diamonds includes a list of 27 color hues

Value and Rarity of Colored Diamonds

• Value of fancy-colored diamonds determined by rarity and intensity of color
• Fashion trends can affect the value of fancy-colored diamonds
• Pink diamonds saw an increase in value after Jennifer Lopez received a pink diamond engagement ring
• Fancy-colored diamonds, such as the deep-blue Hope Diamond, highly sought-after and valuable
• Colored diamonds valued based on clarity and color
• High-color diamonds more valuable due to rarity and consumer demand
• Near-colorless grade diamonds more cost-effective than colorless grade diamonds

Additional Information and Resources

• Diamond clarity is another important factor in evaluating diamonds
• Diamond enhancement techniques can affect the color of diamonds
• Notable diamonds that have gained fame and recognition
• Various organizations, such as GIA and AGS, play a role in diamond grading and certification
• References and further reading materials available for more information on colored diamonds
• GIA Color Scale developed by the Gemological Institute of America
• Importance of diamond color in evaluating diamond quality
• Understanding diamond color essential for informed purchasing decisions

Diamond color Data Sources