Creedite, Durango, Mexico. Probably but not confirmed from the Navidad Mine. This specimen cost me the princely sum of US$ 3.00. It's a perfectly undamaged creedite sphere of about 6 mm in diameter. The creedite, sitting on quartz, fluoresces a beautiful blue in SW and MW UV. The photo's are stacks of 40 images, taken in halogen light and MW-UV.