Description
The Franklin mining district is one of the true “celebrity” localities in the world of mineralogy and mineral collecting. The area sits atop an ore deposit historically exploited for zinc. What made the mine famous is the remarkable abundance of rare mineral species found there—some occurring only at this locality and nowhere else on Earth—as well as its spectacular array of fluorescent minerals, which earned Franklin the moniker “Fluorescent Mineral Capital of the World”. The specimen shown here consists of well-formed black octahedral crystals of franklinite (type-locality) with a metallic lustre, associated with white calcite. When tested under 395 nm ultraviolet light, the calcite fluoresces a red-orange color and then displays a degree of phosphorescence afterward. A small label that was attached to the specimen (now detached from the specimen but will be included with it upon shipping) notes that it originated from F. Fournace [sic]. This detail allows us to determine that the specimen was mined before 1913, the year when the locality’s name changed from Franklin Furnace to Franklin.
LOCATION
USA, New Jersey, Franklin
SIZE
5.3 cm
WEIGHT
73 g