Western United States Rocks

Hogan and Purple Passion Claims Arizona

These ugly appearing, palm to hand sized rocks are interesting geologically. And they are spectacularly fluorescent. Fluorescent rocks from the Hogan and Purple Passion Claims are some of the world’s best.

  • fluorite – blue
  • calcite – dull red to bright reddish orange
  • willemite -green
  • aragonite – aqua


This palm sized thunder egg is unusual. Rather than being filled with water line chalcedony, it’s got green glowing chalcedony tubes.

Chalcedony, a quartz mineral, isn’t fluorescent self. But out west, it sucks up highly fluorescent uranyl ions, which are derived from widely distributed volcanic rocks. It seems everything chalcedony glows green out west.


<more rocks>