I had been wanting a Zacatecas hyalite ever since I first saw it at Jim's house. He had a wonderful specimen that had quite a large amount of daylight fluorescence. While I still haven't found my perfect specimen containing nothing but daylight fluorescing hyalite, this specimen did catch my interest. It has some unusual columnar hyalite crystals that are daylight fluorescing. It's been well documented that the cause of the fluorescence is a large amount of uranyl ions (though not that large. We're still talking parts per million) and it's fairly radioactive. Nothing too crazy. It only hit a max of 2400 CPM with a background of 140-150 as you'll see in the video following.
Locale: Zacatecas, Mexico
Weight: 5.2oz | 148g
Dimensions: 3.2 x 2.7 x 1.4 in | 80 x 69 x 35 mm