"Apple Green" Willemite from Franklin, New Jersey
Contributed by: FMS Admin
minID: 43H-F3E
Date: May 13th, 2026
Locality: Franklin Mine, Franklin, Sussex County, New Jersey, USA (See on Mindat)
Size: 4.5 x 3 x 7.6 cm
Description:
Shown in this post is my very first good quality specimen of "apple green" willemite aka "daylight willemite" from the world-famous Franklin Mining District, Sussex County, New Jersey. Before I recently acquired it, the only specimen of "apple green" willemite I had was much smaller and had much less fluorescent coverage (it contained a lot of non-fluorescent franklinite grains).
Like other specimens of this variety of willemite, the green color is much more vibrant in daylight, due to the blue light and UV components of sunlight trigger "daylight fluorescence". It also fluoresces under 450 nm blue LED light. It is incredibly bright under shortwave UV, and bright under longwave UV.
Originally posted by Frédéric Messier Leroux on Nature's Rainbows in 2022.
Summary of luminescence responses:
Willemite (Mindat) (RRUFF)
- Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Green
- Fluorescence under Blue light (450nm LED): Green
- Fluorescence under Longwave (365nm LED) UV light: Green