yellow fluorescense

[ru486]

I had a piece of 0.25ct G SI1 diamond(sorry, tiny one and no certificate) and I brought to show my friend (She is a GG and Appraiser). She states it has medium yellow fluorescense. Is that normal? I l only heard blue fluorescense, but yellow.... (She said she only saw 3 stones in yellow fluorescense within last 20 years) Should I keep it? or it worths nothing. Please help~~

 

[DiamondExpert]

While blue is the predominant fluorescent color (~90%) of colorless gem quality diamonds, yellow and many other colors, are also seen, although less frequently. In the fancy yellows it's more commonly found.

The example below contrasts med. blue and more faint yellow in E and G colored stones, respectively. The stone on the right is negative and the color you see is due to reflections of the UV tube.

In a colorless stone yellow fluorescence may have a negative impact on apparent color in some lighting where UV is present.