Willemite-Franklinite in 5x5 box.
35 units Lot
Highly fluorescent in ultraviolet light.
Provenance: New Jersey (USA)
Willemite, Franklinite, are two different minerals, which are always associated in the deposit of this locality (Franklin, New Jersey, USA).
Franklinite is an oxide of zinc, iron and manganese.
Willemite, on the other hand, is an oxide of zinc with silicon. This mineral is highly fluorescent, giving a very striking green colour.
This association of minerals is also accompanied by Calcite, which gives an intense pink tone in ultraviolet light.
