Zincite is a distinctive reddish-colored zinc oxide mineral (ZnO). Pure ZnO is white, but natural zincite is red due to Fe+3 impurities. Zincite is a rare mineral. Only one place on Earth has zincite in abundance - the Franklin and Sterling Hill areas of northern New Jersey, USA.
Zincite has a nonmetallic, glassy luster, usually a deep red color, a hardness of 4, one cleavage plane and one parting plane, and is fairly heavy for its size. It is almost invariably associated with franklinite, calcite, and willemite.
Zincite (~1 mm each) from residue of crushed zinciferous marble (zinc ore: franklinite-zincite-willemite-calcite rock). From the Mesoproterozoic-aged Franklin Marble at the Sterling Hill Mine in Franklin, northern New Jersey, USA.