The lead mineralization of the Mibladen district is classic Mississippi Valley Type geology. Vanadinite is hosted within lower Jurassic in the form of stratabound veins in marls and dolomites. A good article was just published in the May/June 2013 issue of the Mineralogical Record written by Tomasz Praszkier of Spirifer Minerals. The Spirifer guys take regular trips to these mines.
This specimen is a high luster, deep red, gorgeous group of hexagonal crystals to 1.5cm. No damage. Excellent specimen.
Vanadinite
Formula
Pb5(VO4)3Cl
Crystal System
Hexagonal
Crystal Habit
Globular, Prismatic, Nodular
Cleavage
None, None, None
Luster
Adamantine
Color
brown, brownish yellow, brown red, colorless, yellow