Semseyite is a rarely occurring sulfosalt mineral and is part of the class of lead

Lead

Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...

 antimony

Antimony

Antimony is a toxic chemical element with the symbol Sb and an atomic number of 51. A lustrous grey metalloid, it is found in nature mainly as the sulfide mineral stibnite...

 sulfides. It crystallizes in the monoclinic system with the chemical composition Pb₉Sb₈S₂₁. The mineral forms dark gray to black aggregates.

Etymology and history

Semseyite was first described for an occurrence in the Felsöbánya mine in Baia Sprie

Baia Sprie

Baia Sprie is a town in the Maramureş County, northern Romania. The Hungarian version of the town's name means "Upper Mine".The town administers three villages: Chiuzbaia, Satu Nou de Sus and Tăuţii de Sus. Neighbouring communities are the city of Baia Mare and the villages of Groşi, Dumbrăviţa,...

, Romania

Romania

Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...

 in 1881 by József Sándor Krenner

József Sándor Krenner

József Sándor Krenner or Joseph Krenner was an Hungarian mineralogist. He discovered several new minerals....

 (1839-1920). The mineral was named after Hungarian mineralogist Andor von Semsey (1833-1923).

Occurrence

Semseyite forms in hydrothermal solutions at temperatures between 300 and 350 °C. It occurs in association with bournonite

Bournonite

Bournonite is a sulfosalt mineral species, a sulfantimonite of lead and copper with the formula PbCuSbS3.It was first mentioned by Philip Rashleigh in 1797 as an ore of antimony and was more completely described in 1804 by French crystallographer and mineralogist Jacques Louis de Bournon , after...

, jamesonite

Jamesonite

Jamesonite is a sulfosalt mineral, a lead, iron, antimony sulfide with formula Pb4FeSb6S14. With the addition of manganese it forms a series with benavidesite. It is a dark grey metallic mineral which forms acicular prismatic monoclinic crystals. It is soft with a Mohs hardness of 2.5 and has a...

, sphalerite

Sphalerite

Sphalerite is a mineral that is the chief ore of zinc. It consists largely of zinc sulfide in crystalline form but almost always contains variable iron. When iron content is high it is an opaque black variety, marmatite. It is usually found in association with galena, pyrite, and other sulfides...

, zinkenite

Zinkenite

Zinkenite is a steel-gray metallic sulfosalt mineral composed of lead antimony sulfide Pb9Sb22S42. Zinkenite occurs as acicular needle-like crystals....

, sorbyite, guettardite

Guettardite

Guettardite is a rare arsenic-antimony lead sulfosalt mineral with formula Pb2S4. It forms gray black metallic prismatic to acicular crystals with monoclinic symmetry. It is a dimorph of the triclinic twinnite.-Discovery and occurrence:...

, jordanite

Jordanite

Jordanite is a sulfosalt mineral with chemical formula Pb146S23 in the monoclinic crystal system, named after the German scientist Dr H. Jordan who discovered it in 1864....

, diaphorite, galena

Galena

Galena is the natural mineral form of lead sulfide. It is the most important lead ore mineral.Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms...

, pyrite

Pyrite

The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...

, chalcopyrite

Chalcopyrite

Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical composition CuFeS2. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green tinged black.On exposure to air, chalcopyrite...

, tetrahedrite

Tetrahedrite

Tetrahedrite is a copper antimony sulfosalt mineral with formula: 12Sb4S13. It is the antimony endmember of the continuous solid solution series with arsenic bearing tennantite. Pure endmembers of the series are seldom if ever seen in nature. Of the two, the antimony rich phase is more common...

, arsenopyrite

Arsenopyrite

Arsenopyrite is an iron arsenic sulfide . It is a hard metallic, opaque, steel grey to silver white mineral with a relatively high specific gravity of 6.1. When dissolved in nitric acid, it releases elemental sulfur. When arsenopyrite is heated, it becomes magnetic and gives off toxic fumes...

 and siderite

Siderite

Siderite is a mineral composed of iron carbonate FeCO3. It takes its name from the Greek word σίδηρος sideros, “iron”. It is a valuable iron mineral, since it is 48% iron and contains no sulfur or phosphorus...

.