Sphalerite is a mineral that is the chief ore of Zinc. It consists mainly of Zinc Sulfide in crystalline form but almost always contains valuable Iron. When the Iron content is high, it is an opaque black variety called Marmatite. It is usually found in association with Galena, Pyrite, Calcite, Dolomite and Fluorite. It is usually yellow, brown or gray to gray-black in color and may have a shiny or dull luster or sheen.
Boulangerite is needle-like crystals, rarely rings, fibrous, compact masses. Named for Charles Louis Boulanger, the French mining engineer who was the first to call the species to attention. Boulangerite is relatively common and widespread, and can be found in medium to high-temperature hydrothermal veins. Some of the many localities include in France, Italy, Sweden, Germany, Serbia, the Czech Republic, the United States, Mexico, and Canada. Minerals associated with Boulangerite include lead sulfosalts, galena, stibnite, sphalerite, pyrite, arsenopyrite, siderite, and quartz. Sometimes easily confused with jamesonite.