Baumhauerite (Pb₃As₄S₉) is a rare

lead Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...

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 (element), mercury, zinc, vanadium *B usually represents semi-metal such as arsenic, antimony, b ...

. It crystallizes in the

triclinic 180px, Triclinic (a ≠ b ≠ c and α ≠ β ≠ γ ) In crystallography, the triclinic (or anorthic) crystal system is one of the 7 crystal systems. A crystal system is described by three basis vectors. In the triclinic system, the crystal is ...

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

, is gray-black to blue-gray and its

lustre Lustre or Luster may refer to: Places * Luster, Norway, a municipality in Vestlandet, Norway ** Luster (village), a village in the municipality of Luster * Lustre, Montana, an unincorporated community in the United States Entertainment * '' ...

is metallic to dull. Baumhauerite has a

hardness In materials science, hardness (antonym: softness) is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion. In general, different materials differ in their hardness; for example hard ...

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. An alternative name sometimes used for the dolomiti ...

marble Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or Dolomite (mineral), dolomite. Marble is typically not Foliation (geology), foliated (layered), although there are exceptions. In geology, the ...

. 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 val ...

Binnental The Binn Valley (German: ''Binntal'') is a valley of the Alps, located on the north side of the Lepontine Alps in the Swiss canton of Valais. The valley is drained by the ''Binna'', a tributary of the Rhone, at Grengiols. The valley is named afte ...

, in the

Valais Valais ( , , ; frp, Valês; german: Wallis ), more formally the Canton of Valais,; german: Kanton Wallis; in other official Swiss languages outside Valais: it, (Canton) Vallese ; rm, (Chantun) Vallais. is one of the cantons of Switzerland, 26 ...

region of

Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...

, 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) properties of minerals and mineralized artifacts. Specific studies within mineralogy include the proces ...

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

(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 Mine Tour & Museum of Fluorescence, is a former iron and zinc mine in Ogdensburg, Sussex County, New Jersey, United States. It was the last working underground mine in New Jersey when it c ...

New Jersey New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware ...

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

, 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 ato ...

, 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 ...

Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central Ca ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

References

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

See also

References