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!

Prehnite from Merelani Hills, Arusha, Tanzania

Contributed by: Mark Cole
Date: Apr 9th, 2026
Locality: Merelani Hills, Lelatema Mountains, Simanjiro District, Manyara Region, Tanzania (See on Mindat)
Size: 1 x 1 x 2 inches
Weight: 1.6 oz

Description:
This is a Prehnite from Merelani Hills, Arusha, Tanzania. A group of nice blue crystals with a light sprinkling of graphite matrix. Interestingly, the best fluorescence is under LW. SW shown for reference only.

Originally posted by Mark Cole on Nature's Rainbows in 2017.

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

Summary of luminescence responses:

Prehnite (Mindat) (RRUFF)

  • Fluorescence under Longwave (365nm LED) UV light: Blue

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