For the Slickenside Aficionado. Super-smooth Phosphorescent Red Willemite, which fluoresces green under 254 Shortwave UV light, interspersed with Calcite (fluoresces red) and crystals of non-fluorescent Franklinite create a striking large cabinet specimen. A Slickenside, geological evidence by way of a "smoothly polished surface caused by frictional movement between rocks along the two sides of a fault. ", Collected from the then-active, legendary Franklin Mine in Franklin NJ, one of the most unique geological assemblages on the planet. 5.5" x 2.5" x 4", 2.55 lbs