Willemite, Calcite - image 1

Willemite, Calcite

TH
Tom Hughes
0 for sale
Help improve this recordNo owner is registered for this specimen yet. If it's yours or you know more about it, you can add the owner, provenance, publications and other details.
Sign in to contribute
Willemite and calcite, 6.3 cm, from the Sterling Hill mine, Sussex County, New Jersey; collected in 1966.

Product details

SpeciesWillemite, Calcite
SizeSmall Cabinet
Dimensions6.3 cm
Added on02/13/2026
LocalityUSA, New Jersey, Sterling Hill Mine
Publications
  • Mineralogical Record Self Collected Minerals page 155

Learn more

Willemite
Mineral guide
Learn about Willemite
fluorescent zinc silicate with UV glow; daylight colors range from colorless to pistachio, iconic from Franklin–Sterling Hill and Tsumeb.
Willemite
Regional guide
Willemite from Sterling Hill Mine, New Jersey, USA
Sterling Hill willemite is one of the classic collector materials of American mineralogy: a zinc silicate, Zn2SiO4, that can look modest in daylight and then turn electric green under ultraviolet light. In the best pieces, tan to reddish-brown willemite crystals sit in white calcite with black franklinite and, less commonly, red zincite—an ore assemblage so distinctive that even small fragments announce the Franklin-Ogdensburg district at a glance. The daylight palette is earthy and old-mine: mahogany, brick red, honey brown, buff, white, and black. Under shortwave UV, however, willemite becomes the bright green signal in the rock, while calcite may burn red to orange-red and franklinite stays dark.