On the second floor of the Museum is a small dark room with an unassuming assortment of rocks and minerals originating from the zinc mines in Franklin, New Jersey. The collection was donated by Robert VanCamp of Columbia, N.J. and Joseph Schwetz of Franklin, N.J. Under sunlight and regular incandescent light these rocks appear quite ordinary, dull even. However, when ultraviolet light (sometimes referred to as “black light”) is shone on these rocks they floresce with brilliant green and red colors. Crystals of black franklinite, pink rhodonite, and green and brown willemite floresce because of the high concentration of manganese in the ore. As the properties of these minerals became known in the early 20th century, discarded tailings from the zinc mining began to be collected by local rock hounds. Many of the minerals found in the Franklin mines are found nowhere else in the world.