Fluorescent Zincite from the Sterling Mine, Sterling Hill, New Jersey
Contributed by: Chris Clemens
Date: Apr 21st, 2026
Locality: Sterling Mine, Sterling Hill, Ogdensburg, Sussex County, New Jersey, USA (See on Mindat)
Size: 53 x 29 x 62 mm
Weight: 179 g
Description:
Zincite is considered to be a rare mineral, occurring in quantity at only Franklin and Sterling Hill, New Jersey. In its pure form, zincite consists of zinc oxide (ZnO), which is a white colored chemical compound, but when some of the zinc in the structure is replaced by manganese (Mn), the mineral takes on an orange-brown color. Often found in association with willemite, calcite and franklinite at the New Jersey locations, zincite is not usually fluorescent. However, in some cases the zincite shows a moderate yellow response. This example is such a specimen, collected from the Sterling Mine in Ogdensburg, Sussex County, New Jersey. This rock consists of orange, brown zincite, grey willemite, white calcite and black grains of franklinite. Under shortwave UV the willemite fluoresces bright green and the other minerals show little or no response. Under longwave UV the zincite can be seen fluorescing as small yellow dots and veinlets, while the willemite shows a subdued green response and the calcite glows a dim pale blue.
Originally posted by Chris Clemens on Nature's Rainbows in 2018.
Summary of luminescence responses:
Calcite (Mindat) (RRUFF)
- Fluorescence under Longwave (365nm LED) UV light: Blue
- Fluorescence under Longwave (365nm LED) UV light: Green
- Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Green
- Fluorescence under Longwave (365nm LED) UV light: Yellow