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, Cave-In-Rock, Illinois

Contributed by: Chris Clemens
minID: KNY-KAR
Date: Apr 24th, 2026
Locality: Cave-in-Rock, Cave-In-Rock Mining Sub-District, Hardin County, Illinois, USA (See on Mindat)
Size: 57 x 44.5 x 64.1 mm
Weight: 86 g

Description:
Wheat sheaf bundles of parallel growth calcite crystals on a yellow/brown fluorite matrix, from Cave-In-Rock, Hardin County, Illinois. Under shortwave UV, the calcite shows a bright blue/white, fluorescent response with brief dim phosphorescence. Under longwave UV, the response is a warmer white. The fluorite matrix is poorly fluorescent.

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

Fluorescence under shortwave UV light.
Fluorescence under shortwave UV light.
Fluorescence under longwave UV light.
Fluorescence under longwave UV light.
Normal light.
Normal light.

Summary of luminescence responses:

Calcite (Mindat) (RRUFF)

  • Fluorescence under Longwave (365nm LED) UV light: White
  • Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Blue

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