The Mineral zincite

Zincite is a rare mineral that is insignificant from all but one region in the world. Its bright orange color is very distinctive, as are its mineral association and habits. Pure synthetic Zincite is colorless; its natural orange to red color is caused by impurities of manganese oxide.

Zincite often forms together and is admixed with Franklinite. A typical association is spotted Zincite and Franklinite on a white Calcite matrix, sometimes joined with Willemite. Although Zincite does not fluoresce, its Willemite and Calcite associations are highly fluorescent. Synthetic Zincite has been produced from industrial operations and laboratory production, and this material is very aesthetic and widely available on the mineral market. Much of this material is brightly colored and comes from Poland.

Chemical Formula

ZnO

Composition

Zinc oxide, almost always with small amounts of manganese and iron

Variable Formula

(Zn,Mn,Fe)O

Color

Deep orange-red, bright orange, yellowish-orange, dark brownish-red

Streak

Orange yellow

Hardness

Crystal System

Hexagonal

3D Crystal Atlas
(Click for animated model)

Crystal Forms
and Aggregates

Crystals of Zincite are rare. When they do occur, they are in small pyramidal hexagonal crystals with a pointed termination on one end and flattened base on the other end. Pyramidal faces tend to be horizontally striated. Crystals are usually associated with massive or grainy Zincite. Most crystals are crudely formed; well-formed crystals are very uncommon. Most often massive, encrusting, and grainy.

Transparency

Translucent. Rarely transparent.

Specific Gravity

5.4 - 5.7

Luster

Adamantine to resinous

Cleavage

1,1; Also exhibits basal parting.

Fracture

Conchoidal to uneven

Tenacity

Brittle

Other ID Marks

Lacks fluorescence

In Group

Oxides; Simple Oxides

Striking Features

Color, mineral association, and locality

Environment

In zinc-rich zones of metamorphosed marble.

Rock Type

Metamorphic

Popularity (1-4)

Prevalence (1-3)

Demand (1-3)

Zincite AUCTIONS

USES

Zincite was an important ore of zinc among the zinc ore bodies in the Franklin and Sterling Hill mines when those mines were in operation. Today zincite is a collector's mineral.

NOTEWORTHY LOCALITIES

The only significant producers of naturally occurring Zincite are the world-famous zinc mines at Franklin and nearby Ogdensburg (Sterling Hill), Sussex Co., New Jersey. Zincite has a few worldwide localities where it occurs naturally in microscopic grains. It has also been synthetically produced from industrial smelter operations and slag deposits in several parts of the world. Poland is especially noted for producing synthetic specimens that have become widely available on the collectors market.

COMMON MINERAL ASSOCIATIONS

Calcite, Franklinite, Willemite, Tephroite

DISTINGUISHING SIMILAR MINERALS

The mineral association and locality are sufficient to distinguish Zincite from any other similarly colored minerals.

zincite PHOTOS