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!

Calcite - France Stone Co. Quarry, Grape, Michigan

Contributed by: Chris Clemens
Date: Apr 28th, 2026
Locality: Grape Quarry (France Stone Company), Grape, Raisinville Township, Monroe County, Michigan, USA (See on Mindat)
Size: 35 x 15 x 37 mm

Description:
Here is an interesting little fluorescent specimen from an obscure Midwestern location, consisting of small clusters of honey-colored scalenohedral calcite crystals on a grey limestone matrix. It is from the France Stone Co. Quarry, Grape, Monroe County, Michigan. Under all UV wavelengths, the calcite fluoresces bright blue/white and shows blue/green to green phosphorescence.

Originally posted by Chris Clemens on Nature's Rainbows in 2017.

Fluorescence under longwave UV light.
Fluorescence under longwave UV light.
Afterglow after exposure to longwave UV light.
Afterglow after exposure to longwave UV light.
Fluorescence under midwave UV light.
Fluorescence under midwave UV light.
Afterglow after exposure to midwave UV light.
Afterglow after exposure to midwave UV light.
Fluorescence under shortwave UV light.
Fluorescence under shortwave UV light.
Afterglow after exposure to shortwave UV light.
Afterglow after exposure to shortwave UV light.
Normal light.
Normal light.

Summary of luminescence responses:

Calcite (Mindat) (RRUFF)

  • Fluorescence under Longwave (365nm LED) UV light: White
  • Afterglow after exposure to Longwave (365nm LED) UV light: Green
  • Fluorescence under Midwave (305nm Lamp/Mercury) UV light: White
  • Afterglow after exposure to Midwave (305nm Lamp/Mercury) UV light: Blue
  • Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: White
  • Afterglow after exposure to Shortwave (254nm Lamp/Mercury) UV light: Blue

FMDB Home Page
Submit a new specimen!
My Collection