Semseyite

Semseyit is a rarely occurring mineral from the mineral class of " sulfides and sulfosalts ". It crystallizes in the monoclinic crystal system with the chemical composition Pb9Sb8S21 and developed mostly tabular to prismatic crystals, but also mineral rosette-shaped aggregates of lead- gray to black color.

Etymology and history

Was first found in Semseyit " Mine Baia Sprie " ( Felsöbánya mine ) in Romania, and in 1881 by József Sándor Krenner ( 1839-1920 ). He named the mineral after Andor of Semsey (1833-1923), a Hungarian nobleman and amateur mineralogists.

Classification

In the old classification of minerals according to Strunz ( 8th edition ) of the Semseyit still belonged to the summary section of the sulfosalts. With the 9th edition of the Strunz'schen Mineral classification, this department has been redefined and also precisely divided by the cations involved in the chemical formula. The mineral is now appropriately in the newly formed Department of " sulfosalts with SnS as a model ", where it forms together with Fülöppit, Heteromorphit, Plagionit and Rayit a separate group within the sub-division of SnS sulfosalts of lead as an additional cation.

In the classification of minerals according to the Dana Semseyit is also assigned to the class' sulfides and sulfosalts ". There he finds himself in the department of " sulfosalts with the ratio 2.0 < z / y < 2.49, and the composition (A ) i ( A2 ) j [ Bycz ] ". There is also, together with Fülöppit, Heteromorphit, Plagionit and Rayit the Fülöppitgruppe (monoclinic C2 / c contains Pb, Sb).

Education and Locations

Semseyit differs in hydrothermal solutions at intermediate temperatures between 300 and 350 ° C.. Accompanying minerals include Bournonite, Jamesonite, quartz, sphalerite and Zinckenit.

Apart from its type locality Baia Sprie the mineral in Romania still in the " Mine Herja " ( Baia Mare) and Satu Mare was found. Herja is regarded as one of the best deposits for Semseyit ever, with mineral discoveries between one and three centimeters in size and fan-or rosettenförmigem appearance.

Worldwide, Semseyit so far to 132 localities demonstrated (as of 2009), so among other things, in Jujuy and Salta in Argentina; some regions of the Bolivian department of Oruro and Potosí; in Haskovo in Bulgaria; in the Chinese region Yizhang; several regions vonDeutschland and France; some regions of the UK; in Bhilwara ( India); Iran; Ireland; the Italian regions of Piedmont and Tuscany; on Honshu in Japan; in British Columbia and Ontario in Canada; at the upper mountain on the burner in Austria; Peru; in Maramureş County in Romania; in the eastern and western regions of Siberia; Slovakia; Spain; Bohemia in the Czech Republic; in the Hungarian Mountains Pils and some regions of the United States.

Crystal structure

Semseyit crystallizes in the monoclinic crystal system, space group C2 / c with lattice parameters a = 13.603 Å, b = 11.936 Å, c = 24.453 Å and β = 106.047 °, and four formula units per unit cell