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!

Four-color Specimen from Hasselhojden, Sweden

Contributed by: Michael Crawford
Date: Dec 22nd, 2025
Locality: Hasselhöjden, Grythyttan, Hällefors, Örebro County, Sweden (See on Mindat)
Size: 5 x 9.5 cm

Description:
A four-color specimen from Hasselhojden, Orebro County, Sweden. Hasselhojden is an inactive marble quarry. The four colors are present under shortwave UV illumination. Sphalerite fluoresces yellow-orange, calcite fluoresces red orange, willemite fluoresces green, and hydrozincite fluoresces light blue. The sphalerite also fluoresces yellow orange under longwave and midwave illumination and it has very bright and long-lasting afterglow from exposure to longwave light. The afterglow is less intense from midwave exposure.

The longwave emission spectrum of the sphalerite is a broad peak with a maximum at 572 nm. Under shortwave light the sphalerite peak shifts to a longer wavelength with a maximum at 599 nm. The sphalerite fluorescence is activated by manganese replacing zinc.

Calcite has weak pinkish red fluorescence under midwave UV light. The calcite fluorescence becomes bright red under shortwave UV light. The shortwave emission spectrum of calcite has a bright peak in the ultraviolet with a maximum at 311 nm. The calcite ultraviolet peak is twenty times more intense than the broad visible red peak that has a maximum at 618 nm. The visible red fluorescence is activated by manganese, and the ultraviolet fluorescence is activated by lead.

The shortwave emission spectrum of hydrozincite (Zn5(CO3)2(OH)6) is a broad peak with a maximum at 451 nm. The fluorescence is activated by lead replacing zinc. The green willemite fluorescence is rather dim compared to willemites from other locations.

Fluorescence under shortwave UV light.
Fluorescence under shortwave UV light.
Fluorescence under midwave UV light.
Fluorescence under midwave UV light.
Afterglow after exposure to longwave UV light.
Afterglow after exposure to longwave UV light.
Normal light.
Normal light.
Longwave Emission Spectrum
Longwave Emission Spectrum
Shortwave Emission Spectra
Shortwave Emission Spectra
Ultraviolet fluorescence under shortwave UV light. False color of 310 nm, 350 nm, and 394 nm bandpass images. Calcite is light blue and hydrozincite is red in this false color image
Ultraviolet fluorescence under shortwave UV light. False color of 310 nm, 350 nm, and 394 nm bandpass images. Calcite is light blue and hydrozincite is red in this false color image
Afterglow after exposure to longwave UV light.
Afterglow after exposure to longwave UV light.
Fluorescence under longwave UV light.
Fluorescence under longwave UV light.

Summary of luminescence responses:

Calcite (Mindat) (RRUFF)

  • Fluorescence under Shortwave (255nm LED) UV light: Red
Sphalerite (Mindat) (RRUFF)
  • Fluorescence under Longwave (365nm LED) UV light: Yellow
  • Fluorescence under Midwave (305nm LED) UV light: Yellow
  • Fluorescence under Shortwave (255nm LED) UV light: Yellow
  • Afterglow after exposure to Longwave (365nm LED) UV light: Yellow
  • Afterglow after exposure to Midwave (305nm LED) UV light: Yellow
Hydrozincite (Mindat) (RRUFF)
  • Fluorescence under Shortwave (255nm LED) UV light: Blue
Willemite (Mindat) (RRUFF)
  • Fluorescence under Shortwave (255nm LED) UV light: Green

FMDB Home Page
Submit a new specimen!
My Collection