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!

Xonotlite and Margarosanite, with Roeblingite(?) and Willemite - Franklin New Jersey

Contributed by: Howie Green
Date: Mar 9th, 2026
Locality: Franklin Mine, Franklin, Sussex County, New Jersey, USA (See on Mindat)

Description:
I am not terribly fluent in the rarer assemblages of Franklin minerals, but this piece looks like it has it all. Under shortwave UV bright green fluorescing ever-present willemite dominates but the rarer minerals peek through nicely (two sides shown). Bright bluish is margarosanite, while the violet is xonotlite. The red is likely roeblingite (can someone confirm?) and I assume the orange to be clinohedrite. There are probably some other minerals in this piece also, but beyond my abilities to ID.

Originally posted by Howie Green on Nature's Rainbows.

Fluorescence under shortwave UV light.
Fluorescence under shortwave UV light.
Normal light.
Normal light.
Fluorescence under shortwave UV light. Side 2
Fluorescence under shortwave UV light. Side 2

Summary of luminescence responses:

Margarosanite (Mindat) (RRUFF)

  • Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Blue
Xonotlite (Mindat) (RRUFF)
  • Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Violet
Roeblingite (Mindat) (RRUFF)
  • Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Red
Willemite (Mindat) (RRUFF)
  • Fluorescence under Shortwave (255nm LED) UV light: Green
Clinohedrite (Mindat) (RRUFF)
  • Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Orange

FMDB Home Page
Submit a new specimen!
My Collection