Sterling Hill Fluorescent Zincite
Contributed by: FMS Admin
Date: Mar 20th, 2026
Locality: Sterling Hill, Ogdensburg, Sussex County, New Jersey, USA (See on Mindat)
Size: 3 x 3 inches
Description:
As I\'ve posted before, I am a big fan of powerful, true 365nm UV light from LED flashlights. It allows me to find stuff that is literally invisible to others scanning the same rock pile with SW only. It\'s like having superpower vision. That vision allowed me to find a couple of large pieces in the Sterling Hill Mineral Museum\'s primary collecting area, the Mine Run Dump, of some rare fluorescent Zincite. I was looking for Hydrozincite and took a likely specimen into the SW shack on the premises to check it. The coating I suspected wasn\'t Hydrozincite so, covering all bases, I hit the rock with the 365nm light and was shocked... it was covered with bright, yellow-green flecks. Having never seen that before, I corralled the museum's President who was walking past and he was very pleased to tell me it was rare fluorescent Zincite, which typically does not glow at all.
It is worth nothing that fluorescent tube-based LW does not light up the Zincite nearly as much as does the LED-based light. Again, like the Yellow-Fluorescent-Calcite my other post, it may be that this material is more common than suspected, it\'s just that nobody ever sees it when prospecting. So now knowing what to look for, I quickly found another piece, which hammered along with the first find, has yielded several nice pieces of this uncommon material. Some do have Hydrozincite along with Willemite, Calcite, Sphalerite, and Cleiophane. Seen on this piece in LW are green Willemite, a few spots of bright blue Cleiophane, and the bright yellow green Zincite. The SW photo discloses the Willemite and in the daylight shot you can see the rust-colored Zincite, non-fluorescent, white Calcite, and black crystals of non-fluorescent Franklinite.
Originally posted by Michael Isaacson on Nature's Rainbows in 2016.
Summary of luminescence responses:
Zincite (Mindat) (RRUFF)
- Fluorescence under Longwave (365nm LED) UV light: Yellow
- Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Green