Diamond Fluorescence: Understanding White & Yellow Tones

Question
Hi, I have a one carat ring and an anniversary ring with 7 1/4 c diamonds.  I notice when I am in the tanning bed that the six of the smaller diamonds glow white while the other one and the large diamond are almost a yellow.  Can you tell me what that means?  The larger diamond was purchased about 20 years ago.

Answer
Arlene-
the ultraviolet light highlights the stones which are fluorescent. The higher the fluorescence the more intense the light will be. It will have a bluish haze to it.
Some people do not like these types of stones and in fact the prices on larger stone which fluoresce are slightly lowered price.......
all the best
Les