MCQ Detailed View

The diamond color grading scale used internationally is the D to Z scale, developed by the Gemological Institute of America (GIA). This scale is the global standard for assessing the color of white or colorless diamonds.

How the D to Z Scale Works:

• D: Completely colorless and the rarest. These diamonds are the most valuable.


• E–F: Nearly colorless, with very slight traces of color detectable only by experts.


• G–J: Near colorless. These diamonds appear mostly white but may show slight warmth when compared to higher grades.


• K–M: Faint color. A yellow or brown tint is noticeable but diamonds can still appear attractive in the right setting.


• N–R: Very light color, with more visible yellow or brown tones.


• S–Z: Light color, easily visible tint that reduces value compared to higher-grade stones.

Why the scale starts with D:

Before GIA introduced the system, older grading methods used letters A, B, and C inconsistently. To avoid confusion, the GIA began its system with the letter D to represent the highest quality.

Importance of Diamond Color:

Color is one of the 5 Cs of diamond valuation (Carat, Cut, Clarity, Color, Certification). A diamond’s color directly affects its beauty and price. The closer a diamond is to being colorless, the higher its value. Completely colorless diamonds (D grade) are rare and command premium prices, while diamonds with visible color (closer to Z) are less expensive.

Conclusion:

The correct grading system for diamond color is the D to Z scale, which remains the industry standard for assessing colorless diamonds.