Anna Lee Lode Occurrence, Custer County, Colorado, USA
2 cm x 2.5 cm ugly reddish-brown massive, radioactive. Collected by Hal Miller in 1957. From David Shannon Minerals, via Richard Dale Minerals.
© Jeffrey Shallit 2007
Width of field is 7.0 mm. Collection and photo Jesse Crawford. Compositing software CombineZP. Equipment: Nikon D-100 digital camera on a homemade microscope.
© 2008 by Jesse Crawford
I bought this from Michael Shannon at the Tucson mineral show. My XRF shows Ca, Th, and Fe, the latter being a common impurity.