Manganese mineralization of Maria Theresia vein near Horní Blatná (Bergstadt Platten) in Krušné hory Mts. (Erzgebirge Mts.), Czech Republic

Aleš Bufka – Ministry of Industry and Trade of the Czech Republic, Prague, Czech Republic
Dalibor Velebil – National Museum, Prague, Czech Republic
Bull. mineral.-petrolog. Odd. Nár. Muz. (Praha) 11 (2003), 100–114


Maria Theresia ore vein with manganese mineralisation near Horní Blatná in the Krušné hory Mts. (Erzgebirge Mts., Czech Republic) is a significant mineralogical locality. On the samples of manganese ores was realised one of the first scientific researches of Mn-minerals in the first half of 19th century. In the paper a summary of geology, mineralogy and mining history is given.

Keywords: manganese ores, problems of pyrolusite, polianite, economic geology, history of mining, the Blatná granite massif, Krušné hory Mts.


The vein Maria Theresia is located on the hill called Jeleni Vrch (Hirschberg) southwesterly of Horni Blatna in Krusne Hory Mountains. The vein was opened with several mine works namely in 18th and 19th century. In the 19th century and at the beginning of the 20th century, manganese ores were extracted from the vein. However, the volume of exploitation was not big, as the sale of the manganese ore was limited at the early time; more extensive use came in hand with steel production development and, in second half of the 19th century also with production of chlorine and oxygen. The vein is famous for its rich occurrences of well developed crystals of pyrolusite.

In the Czech mineralogical literature, the locality Horni Blatna is by mistake considered as a type locality of pyrolusite (Velebil 1998, Bernard 2000); according to general opinion, it was first described by Haidinger (1827) (Nickel a Nichols 1991). Haidinger was studying manganese minerals of many mineralogical collections (including mineralogical collection of National Museum in Prague superintended by Zippe) and introduced the name pyrolusite for mineral till then known as Grau Braunstein, Grey Manganese-ore, Grey Oxide of Manganese, or Manganese-Hyperoxide, etc. In his work dated 1827, Haidinger named forty European (namely German) and four Brazilian pyrolusite locations. The European locations include also sites around Horni Blatna (Platten) with iron ore mine Hilfe Gottes as an example (vein Irrgang at Bludna east of Horni Blatna). Haidinger used for his studies namely pyrolusite samples from German locations, e.g. Eiserfeld (locality Tiefe Kohlenbach) near Siegen (Westphalia), Elgersburg (Thuringia) and Öhrenstock near Ilmenau (Thuringia) (Haidinger 1827).

Haidinger included pyrolusite into so called “prismatic” system. At his times the concept of crystal systems corresponded to the present day approach only partly. Haidinger built on the concept of his teacher F. Mohs and the prismatic system included also present orthorhombic (rhombic), monoclinic and triclinic systems. In 1836, F. X. M. Zippe (Zippe 1836) mentions rich and exploitable occurrences of  “prismatic manganese ore” near Horni Blatna. Zippe was also one of the Mohs’s followers who visited the manganese ore mines near Horni Blatna already in 1824. Then, Zippe favored the National Museum with several samples of manganese ores (Figure 1).

In 1843, the Maria Theresia mine at Jeleni hill at Horni Blatna was visited by German mineralogist A. Breithaupt (thanks to the mine owner J. Schlosser) who immediately disseminated from this location black-grey fine grained “soft” pyrolusite (Weichmanganerz) and light-grey visibly crystalline manganese ore (lichte Graumanganerz) which he gave the name polianite (Breithaupt 1844). Breithaupt describes the polianite as “rhombic-prismatic manganese ore (rhombisch-prismatischen Manganerze)” – this corresponds to the present rhombic system. Afterwards, polianite was for certain period considered like distinct mineral specie, though the apprehension and definition of both pyrolusite and polianite underwent a confused and rather chaotic development. Already Haidinger (Haidinger 1845 in Köchlin 1888) refused polianite as a distinct mineral specie considering thereof as a pseudomorph of braunite. Also other authors talk about various types of pseudomorphs of pyrolusite, polianite and manganite (Köchlin 1888; Dana 1892; Kratochvíl 1957 and others).

E. S. and J. D. Dana’s (1880) cited pyrolusite as rhombic MnO2 and polianite as a synonym thereof. In the fifth edition of mineralogical system, Dana (1882) mentioned both pyrolusite and polianite as rhombic minerals, while considered polianite as very pure pyrolusite. Immediately in the following sixth edition (Dana 1892) he described pyrolusite as rhombic mineral and polianite as tetragonal (Figure 2). (Tetragonal system according to Mohs and thus also Haidinger corresponds to “pyramidal (pyramidales)” system and Breithaupt himself is the author of the term tetragonal system that introduced to crystallography). Kopecky (1905–18) reports that “pyrolusite variety polianite crystallizes as hard light grey, metallic luster orthorhombic crystals….The newest findings indicated that this belong to tetragonal system.”

Ford (in Dana and Ford 1932) mentioned pyrolusite as orthorhombic (rhombic) mineral and under the same entry reports that accoridng to x-ray research pyrolusite has the same structure as polianite; however, elsewhere he wrote about polianite as tetragonal mineral.

In 1943, based on x-ray research, Fleischer and Richmond introduced pyrolusite as tetragonal MnO2 and simultaneously brought in the rhombic MnO2 as new mineral specie named ramsdellite (location Lake Valley, Sierra Co., New Mexico, USA). As a basis, they used the former x-ray surveys of manganese oxides of Ramsdell (1932) and John (John 1923 in Ramsdell 1932). Fleischer and Richmond (1943) reported that rhombic MnO2 was likely a transformation product of tetragonal MnO2 while ramsdellite (rhombic) transforms to pyrolusite (tetragonal) at temperature of about 300 °C (Fleischer and Richmond 1943; Fleischer et al. 1962). They abated the name polianite for tetragonal MnO2 as idle, i.e. they identified polianite with pyrolusite (Fleischer and Richmond 1943). In Betechtin’s mineralogy date 1951 pyrolusite is already mentioned as tetragonal mineral while polianite is cited as obsolete synonym for crystalline varieties of pyrolusite (Betechtin 1951). Also in recent literature, the name polianite is considered as synonym to pyrolusite, eventually as “coarse crystalline” or “crystallized” variety of pyrolusite.

Ramsdellite at Horni Blatna was diagnosed almost simultaneously at the beginning of the 1960’s by Bernardová and Slánský (1960) and Neumann (1961). At that time, however, the name polianite was still used for manganese ores from the vein Marie Theresa by Mrňa (Mrňa 1961, Mrňa and Pavlů, 1961).

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