Baumhauerite (Pb₃As₄S₉) is a rare

lead Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleabl ...

sulfosalt mineral Sulfosalt minerals are sulfide minerals with the general formula , where *A represents a metal such as copper, lead, silver, iron, and rarely mercury, zinc, vanadium *B usually represents semi-metal such as arsenic, antimony, bismuth, and rarely ...

. It crystallizes in the

triclinic class=skin-invert-image, 180px, Triclinic (a ≠ b ≠ c ≠ a and α, β, γ, 90° pairwise different) In crystallography, the triclinic (or anorthic) crystal system is one of the seven crystal systems. A crystal system is described by three b ...

system A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its open system (systems theory), environment, is described by its boundaries, str ...

, is gray-black to blue-gray and its lustre is metallic to dull. Baumhauerite has a

hardness In materials science, hardness (antonym: softness) is a measure of the resistance to plastic deformation, such as an indentation (over an area) or a scratch (linear), induced mechanically either by Pressing (metalworking), pressing or abrasion ...

of 3. Baumhauerite occurs as small crystals embedded in

dolomitic Dolomite () is an anhydrous carbonate mineral composed of calcium magnesium carbonate, ideally The term is also used for a sedimentary carbonate rock composed mostly of the mineral dolomite (see Dolomite (rock)). An alternative name sometimes ...

marble Marble is a metamorphic rock consisting of carbonate minerals (most commonly calcite (CaCO3) or Dolomite (mineral), dolomite (CaMg(CO3)2) that have recrystallized under the influence of heat and pressure. It has a crystalline texture, and is ty ...

. It is found primarily in the

Lengenbach Quarry The Lengenbach Quarry is located in the Binn Valley (Valais, Switzerland) and it is noted among the mineralogical community for its unusual sulfosalt mineral specimens. The dolomite hosted deposit of the quarry is in the Binn Valley, a small ...

, Binnental, in the

Valais Valais ( , ; ), more formally, the Canton of Valais or Wallis, is one of the cantons of Switzerland, 26 cantons forming the Switzerland, Swiss Confederation. It is composed of thirteen districts and its capital and largest city is Sion, Switzer ...

region of

Switzerland Switzerland, officially the Swiss Confederation, is a landlocked country located in west-central Europe. It is bordered by Italy to the south, France to the west, Germany to the north, and Austria and Liechtenstein to the east. Switzerland ...

, the mineral is named after German

mineralogist Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical mineralogy, optical) properties of minerals and mineralized artifact (archaeology), artifacts. Specific s ...

Heinrich Adolph Baumhauer Heinrich Adolph Baumhauer (26 October 1848, Bonn, Germany, Bonn, Kingdom of Prussia - 1 August 1926, Freiburg, Switzerland) was a German chemist and mineralogist. Baumhauer was the son of lithographer and merchant Mathias Baumhauer (1810–70) ...

(1848–1926), who discovered it at Lengenbach, famous among mineralogists for its array of rare minerals, in 1902. Baumhauerite has also been reported at

Sterling Hill The Sterling Hill Mine, now known as the Sterling Hill Mining Museum, is a former zinc mine in Ogdensburg, Sussex County, New Jersey, United States. It was the last working underground mine in New Jersey. It closed in 1986, and became a mus ...

New Jersey New Jersey is a U.S. state, state located in both the Mid-Atlantic States, Mid-Atlantic and Northeastern United States, Northeastern regions of the United States. Located at the geographic hub of the urban area, heavily urbanized Northeas ...

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

, typically in association with

molybdenite Molybdenite is a mineral of molybdenum disulfide, Mo S2. Similar in appearance and feel to graphite, molybdenite has a lubricating effect that is a consequence of its layered structure. The atomic structure consists of a sheet of molybdenum at ...

, and in aggregates at Hemlo,

Thunder Bay Thunder Bay is a city in and the seat of Thunder Bay District, Ontario, Canada. It is the most populous municipality in Northwestern Ontario and the second most populous (after Greater Sudbury) municipality in Northern Ontario. Its population i ...

Ontario Ontario is the southernmost Provinces and territories of Canada, province of Canada. Located in Central Canada, Ontario is the Population of Canada by province and territory, country's most populous province. As of the 2021 Canadian census, it ...

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

References

Lead minerals Arsenic minerals Sulfosalt minerals Triclinic minerals Minerals in space group 1 {{sulfide-mineral-stub

See also

References