Fluorescent Mineral Database

A new secret project! Trying to create a nice Fluorescent Mineral Database (FMDB), which would be searchable by mineral, locality, and luminescence properties. Also making it easy for people to contribute with their own specimens!

Gem Willemite from Franklin, New Jersey

Contributed by: Michael Crawford
Date: Jun 21st, 2025
Locality: Franklin Mine, Franklin, Sussex County, New Jersey, USA (See on Mindat)
Size: 7 x 9

Description:
This is a green gemmy willemite from the Franklin Mine, Franklin, New Jersey. The willemite fluoresces bright green under all wavelengths of UV illumination. The specimen also has daylight fluorescence. It has a more vibrant green color in sunlight compared to the white light image taken with LED’s. The shortwave emission spectrum has a maximum of 525 nm. Other green fluorescent willemite specimens have peaks that range from 518 nm to 525 nm.

Fluorescence under shortwave UV light.
Fluorescence under shortwave UV light.
Normal light.
Normal light.
Daylight fluorescence.
Daylight fluorescence.
Shortwave Emission Spectra
Shortwave Emission Spectra

Summary of luminescence responses:

Willemite

  • Fluorescence under Longwave (365nm LED) UV light: Green
  • Fluorescence under Midwave (305nm LED) UV light: Green
  • Fluorescence under Shortwave (255nm LED) UV light: Green
  • Fluorescence under Daylight: Green

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