Zincite from the Sterling Hill Mine, Ogdensburg, Sussex County, New Jersey
Contributed by: Michael Crawford
Date: Sep 27th, 2025
Locality: Sterling Mine, Sterling Hill, Ogdensburg, Sussex County, New Jersey, USA (See on Mindat)
Size: 7 x 9.5 cm
Description:
A specimen with a vein of orange zincite (ZnO) and calcite (CaCO3) in a matrix of brown willemite (ZnSiO4), white calcite, black franklinite (ZnFe2O4), and red zincite (ZnO). The specimen is from the Sterling Hill Mine, Ogdensburg, Sussex County, New Jersey. The orange zincite in the vein fluoresces bright pale yellow under longwave UV illumination. It is dimmer under midwave and shortwave UV light. The longwave emission spectrum is a single broad peak with a maximum at 504 nm. Manganese is a possible activator for the zincite fluorescence. The red zincite in the matrix is non-fluorescent as is most zincite.
The willemite in the matrix fluoresces bright green under shortwave UV illumination. It is dimmer under midwave and longwave light. It has afterglow from exposure to shortwave and midwave light. Manganese replacing zinc activates the green fluorescence. Its shortwave emission spectrum is much narrower compared to the zincite spectrum. The willemite spectrum has a maximum at 521 nm.
The calcite fluoresces red under all wavelengths of illumination. It is brightest under shortwave light. Manganese replacing calcium activates the red fluorescence. The emission spectrum is a broad peak with a maximum at 614 nm.
Summary of luminescence responses:
Zincite (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: Green
- Afterglow after exposure to Shortwave (255nm LED) UV light: Green
- Fluorescence under Shortwave (255nm LED) UV light: Red