Fluorescent Yellow Chalcedony/Chert from Milwaukee Co, Wisconsin. 260 grams.

Description

Beautiful Grey/Blue Chalcedony/Chert nodule that fluoresces a nice bright yellow under a good long wave UV light (365nm). Very attractive sample.
Found in Milwaukee County Wisconsin along the lake Michigan shoreline.
I am not certain of the reactive element that causes it but possibly a carbonate mineral.
260 grams
3" in length.
NOTE!
Photos taken with a 365nm Convoy2 band pass filtered Long Wave UV light, if you use any other type of UV light you may get different results.