Beautiful 3-Color Rock from Franklin, New Jersey

Contributed by: Chris Clemens
minID: DP7-F6C
Date: Apr 23rd, 2026
Locality: Franklin Mine, Franklin, Sussex County, New Jersey, USA (See on Mindat)
Size: 6 x 4.8 x 6.4 cm
Weight: 268 g

Description:
This is a truly classic 3-color fluorescent rock from the Franklin Mine, Franklin, New Jersey. This technicolor specimen provides a spectacular example of why Franklin is known as the Fluorescent Mineral Capital of the World. When viewed under visible light, this specimen features light colored hardystonite, willemite and calcite, and dark olive/brown andradite garnet. Under shortwave UV, the hardystonite fluoresces blue, the willemite bright green, and the calcite red/orange. The andradite is not fluorescent.

Originally posted by Chris Clemens on Nature's Rainbows in 2016.