UV fluorescence on two geodes

I like to try Ultra Violet (UV) fluorescence on different subjects. Here I an showing how two geodes react differently to UV light. I am showing these using a comparison slider so the difference between ‘daylight’ and UV light can be seen. Drag the slider to show/hide the images.

First as a ‘normal’ geode with the daylight on the left and the UV fluorescence on the right:

This a composite image from the above 2 photos:

This didn’t react very well to UV, it just showed a dark blue colour. But this next one really surprised me:

And this is the composite version of the 2 photos:

I have never seen white UV fluorescence before. Nature can be quite surprising…