Zincite, ZnO (zinc oxide), and franklinite (zinc iron manganese oxide) are rare and inconspicuous at all but one general site. That site is the famous zinc and — Photo: Darla Sondrol · CC0
Zincite
Zinc oxide — deep-red hexagonal crystals, famously abundant (and fluorescent) at Franklin, New Jersey.
Intro adapted from Wikipedia (CC BY-SA).
Zincite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula ZnO.
It crystallizes in the hexagonal crystal system (space group P6_3mc). It is a member of the Wurtzite structural group.
Key properties: Mohs hardness 4–4.5; specific gravity 5.66; typically red or orange or yellow; Yellow-orange streak; Subadamantine to resinous luster; refractive index 2.021; optically uniaxial.
IMA symbol Znc, grandfathered status — known before the IMA’s founding, named in 1845.
Found as a primary mineral in metamorphosed stratiform zinc orebodies (New Jersey, USA); a secondary mineral altered from other zinc minerals in oxidized zinc-rich ore deposits; a product of volcanism.
It is found associated with Franklinite, willemite, calcite (New Jersey, USA); zinc, sphalerite, smithsonite, hemimorphite, hausmannite.
The name refers to ZINC in the composition.
Collections: Collector Favorites, Rare & Remarkable.