This is an interesting specimen of colorless, banded, quartz that was dug up in a farm field in Cato Township, Manitowoc County, Wisconsin. Under short wave UV, a blue, banded, fluorescent response is seen with teal green streaks. The long wave response is a more uniform blue/purple color. This specimen is also dimly phosphorescent following exposure to short wave UV. 10.2 x 7.6 x 6.4 cm, 685 gms.
The specimen is shown under short wave UV (left), long wave UV (center), and visible light (right). Click on individual images for a larger view.