Sfaleeriitti

Sfaleeriitti is a mineral composed of zinc sulfide (ZnS). It is the most important ore of zinc and is often found in hydrothermal veins, sedimentary rocks, and metamorphic rocks. Its name comes from the Greek word "sphaleiros," meaning "treacherous," a reflection of its often confused identity with other minerals like galena.

The color of sfaleeriitti can vary widely, ranging from colorless and white to yellow, brown, and even black. This variation is due to the presence of impurities such as iron, cadmium, manganese, and copper. Pure sfaleeriitti is colorless, but these trace elements cause it to absorb light and appear colored. It typically has a resinous to adamantine luster and a white to pale yellow streak.

Sfaleeriitti crystallizes in the isometric system, forming tetrahedral or dodecahedral crystals, though massive and granular aggregates are also common. It is relatively soft, with a Mohs hardness of 3.5 to 4, and has a specific gravity of around 4.0 to 4.1. It is insoluble in water but can be dissolved in hydrochloric acid.

Economically, sfaleeriitti is the primary source of zinc, a metal crucial for galvanizing steel, producing brass, and in various chemical compounds. Significant deposits are found worldwide, with major producing countries including China, Australia, Peru, and Mexico. Its co-occurrence with other valuable minerals like galena (lead sulfide) and chalcopyrite (copper iron sulfide) makes mining operations complex but potentially very profitable.