What does the Z color grade signify in diamond color?

• A. Very light yellow or brown tint.
• B. Deep yellow or brown hue
• C. No color, completely colorless
• D. Blue tone color

Answer: (A)

The main idea is that color grading for white diamonds runs from colorless to tinted, with Z representing the far end of the scale. Z indicates a noticeable yellow or brown tint, rather than no color at all. This tint is what sets Z apart from higher-grade, colorless stones and becomes more visible in larger stones or when placed next to purer-colored gems. The grading is done under controlled lighting using master stones to compare how much color is present. So, describing a very light yellow or brown tint correctly captures what Z signifies. The other descriptions don’t fit: no color would be colorless (higher up the scale), a deep yellow or brown hue would fall at a different, lower portion of the scale, and blue tones aren’t part of the standard white-diamond color grading.