Boulangerite Calcite Naturally Terminated Yugoslavia 328g

Mineral Name: Boulangerite Chemical Formula: Pb5Sb4S11 - Lead Antimony Sulfide Color: Boulangerite is typically dark steel-gray to black in color. It may exhibit metallic luster, and the crystals often have a prismatic or fibrous habit. Crystal System: Monoclinic Hardness: 2.5 on the Mohs scale Luster: Metallic Transparency: Opaque Specific Gravity: 5.75 - 6.0 Cleavage: Indistinct Fracture: Irregular to subconchoidal Streak: Black Occurrences: Boulangerite is commonly found in hydrothermal veins associated with other sulfide minerals, especially in lead-zinc ore deposits. Notable occurrences include Germany, Romania, Mexico, Peru, and the United States. Notable Localities: Some significant boulangerite localities include the Herja mine in Romania, the Trepča Mines in Kosovo, and the Sweetwater Mine in Missouri, USA. Formation: Boulangerite typically forms in hydrothermal environments, where hot mineral-rich fluids interact with host rocks. It often occurs as prismatic crystals or fibrous aggregates in association with other sulfide minerals, such as galena and sphalerite. Unique Features: Boulangerite crystals can exhibit a prismatic habit, and the mineral often forms fine, fibrous aggregates. The metallic luster and dark color contribute to its distinctive appearance. Boulangerite is a member of the cylindrite group, which includes minerals with a similar crystal structure. Uses: Boulangerite is not widely used for commercial purposes due to its low hardness and association with sulfide ores. However, it is of interest to mineral collectors and researchers studying ore deposits and mineralogy. Caution: Boulangerite contains lead and antimony, both of which can be toxic. As with other lead-containing minerals, care should be taken when handling specimens, and contact with the mouth or ingestion of dust particles should be avoided. Proper hygiene practices, such as washing hands after handling, are recommended.