VANADINITE

ABOUT THE SPECIMEN Large specimen with numerous groupings of vanadinite, colored brick-red to almost black in some parts. Some of the crystals are free standing, and many others joined together in tight clusters. For how large of a specimen this is, it’s impressive to note how dense the coverage is, with large crystals present in each area.   MORE INFO Mibladen is a stratiform Pb-Ba deposit hosted in Lower Jurassic (Liassic) limestones and dolomites of the High Atlas approximately 25 km northeast of Midelt, mined commercially for lead by French operators from the mid-1930s until closure in 1983. Vanadinite formed secondarily as the arid climate of the Atlas facilitated oxidation of galena without the interference of significant rainfall; vanadium sourced from the surrounding sedimentary sequence combined with lead in the oxidation zone to precipitate the hexagonal lead chlorovanadate. Crystals are typically thick tabular to prismatic hexagonal prisms, predominantly deep red to orange-red, with color zoning occasionally visible as a saturated orange core transitioning to deeper red toward the prism terminations; a rare subset displays skeletal growth on prism faces producing a translucent cat's-eye effect when viewed down the c-axis. Most specimens are floaters or occur on tan baryte and limonite matrix. Since the industrial closure, the deposit has been worked periodically by small-scale Moroccan miners sinking shallow shafts from surface - a 2019 discovery sparked a significant mining rush producing new material after years of the market depending entirely on old stock. Praszkier's 2013 Mineralogical Record account remains the definitive published treatment of the locality.