'Youbai' refers to diamonds of F-G color grade. GIA divides the colors of common colorless diamonds into 23 levels and represents them with English letters such as D, E, F, G-Z, etc. In some national diamond grading standards, text can also be used to represent the color of inlaid diamonds.
What are the diamond grades
1. D-E grade: extremely white, also known as "special white", "extremely bright white", "clean water color"
D color: pure colorless, extremely transparent, visible extremely light blue.
E color: pure colorless, extremely transparent.
2. F-G grade: Excellent White, also known as "Bright White"
F color: It appears colorless and transparent from any angle.
G color: Diamonds weighing less than 1ct appear colorless and transparent when viewed from the crown and pavilion, while diamonds weighing more than 1ct display a faint yellow (brown, gray) hue when viewed from the pavilion.
3. H-level: White
H color: white. Diamonds below 1ct cannot be seen to have any color tone from the crown, while from the pavilion, a faint yellow (brown, gray) tone can be seen.
4. I-J grade: Slightly yellow (brown, gray) white, also known as "pale white" or "commercial white"
Color I: Diamonds with a crown size of less than 1ct appear colorless upon observation, while those with a crown size of less than 1ct appear slightly yellow (brown, gray) upon observation.
J color: Diamonds with a crown size of less than 1ct appear almost colorless when observed, while those with a crown size of less than 1ct appear slightly yellow (brown, gray) when observed in the pavilion.
5. K-L grade: light yellow (brown, gray) white
K color: The crown appears light yellow (brown, gray) white when observed, while the pavilion appears very light yellow (brown, gray) white when observed.
L color: The crown appears light yellow (brown, gray) when observed, and the pavilion appears light yellow (brown, gray) when observed.
6. M-N level: light yellow (brown, gray) color
M color: The crown appears light yellow (brown, gray) when observed, while the pavilion has a distinct light yellow (brown, gray) color when observed.
N color: Diamonds have a distinct light yellow (brown, gray) color when viewed from any angle.
7. For this type of diamond, non professionals can see that it has a distinct yellow (brown, gray) color
Therefore, the diamond color "Youbai" refers to diamonds of F-G color level.