Kleberite

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Kleberite
General and classification
other names
  • IMA 2012-023
  • Hydroxyl pseudorutile (hydroxylian pseudorutile)
chemical formula Fe 3+ Ti 6 O 11 (OH) 5
Mineral class
(and possibly department) 		Oxides and hydroxides
System no. to Strunz
and to Dana 		4.CB.
07.11.10.01
Crystallographic Data
Crystal system monoclinic
Crystal class ; symbol monoclinic prismatic; 2 / m
Space group P 2 1 / c (No. 14)Template: room group / 14
Lattice parameters a  = 7.537  Å ; b  = 4.5795 Å; c  = 9.885 Å
β  = 131.02 °
Physical Properties
Mohs hardness 4 to 4.5
Density (g / cm 3 ) 3.28 (measured); 3.91 (calculated)
Cleavage well parallel and perpendicular to the c-axis [0001] of the precursor mineral ilmenite
Break ; Tenacity uneven to rough with finely grooved surface; brittle
colour red-brown to orange (depending on the Fe content)
Line color beige
transparency translucent
shine Wax to glass gloss, semi-metallic diamond gloss on fresh fractured surfaces
Crystal optics
Refractive index n  = 2.090 to 2.225 (measured), 2.16 (calculated)
Birefringence δ = 0.04 to 0.05
Optical character uniaxial negative, occasionally anomalous biaxial negative
Axis angle 2V = ≈ 0 °, if abnormally biaxial
Other properties
Special features weakly ferromagnetic (hydroxyl pseudorutile, Murray Basin)

Kleberite is a very rarely occurring mineral from the mineral class of " oxides and hydroxides ". It crystallizes in the monoclinic crystal system with the chemical composition FeTi 6 O 11 (OH) 5 , so from a chemical point of view it is an iron - titanium - oxide - hydroxide . Its type locality is tertiary alluvial sands near Königshain-Wiederau ( coordinates of Königshain / Saxony ) not far from Mittweida in Saxony, Cotyp localities are the Murray Basin, Southeast Australia, and Borneo (Kalimantan), Indonesia.

So far, Kleberite has only been found in the form of loose, single-crystalline grains, the size of which varies between 0.040 mm and 0.5 mm. In addition, it forms rhombohedral crystals that represent pseudomorphoses according to ilmenite .

Etymology and history

“Kleberit has a very long and eventful history behind it. At first it was described very incompletely and without recognition from the IMA, then officially discredited, considered a variety of pseudorutil and finally submitted to the IMA and recognized over 30 years after it first appeared in the official literature. This story reflects the secrecy policy in the GDR with regard to raw material issues, but also misinterpretations and the overlook of obvious contradictions. The successful characterization of the glueite can also be traced back to the advances in analytical technology over the last few decades. "

- Thomas Witzke

The mineralogist Klaus Steinike at the Central Geological Institute (ZGI) Berlin, who described the mineral in 1963 as part of the uranium exploration due to its striking optical properties from heavy mineral fractions of tertiary sands in northeast Germany on the former territory of the GDR , is considered the discoverer of the Kleberite . It was named "Kleberit" in the 1970s in honor of Professor Dr. habil. Wilhelm “Will” Kleber (1906–1970), but only internally and without recognition by the International Mineralogical Association (IMA). A publication did not take place until 1978 for reasons of confidentiality. Kleber was a professor at the Humboldt University in Berlin and director of the Mineralogical-Petrographic Institute and the Museum of Natural History at the Humboldt University in Berlin.

For more than a decade, the "Kleberite" was part of the exploration for uranium deposits and was therefore subject to the strict confidentiality regulations in the GDR. By circumventing the restrictive safety regulations of the ZGI, the discovery of "Kleberite" was published in 1978 under the leadership of the Humboldt University of Berlin with additional data. However, the description was rejected as unsatisfactory as early as 1979. The name "Kleberit" was not approved. As only recognized in 2011, the structural analysis was carried out on a “non-Kleberite”.

On the basis of similar (not identical) structural data of the German “Kleberite” from 1978 with an Australian mineral from the Murray-Darling Basin in New South Wales (Australia) that was exactly examined and described by Ian E. Gray , John A. Watts and Peter Bayliss ) the name "Hydroxyl-Pseudorutil" became official in 1994. An attempt by the IMA's nomenclature commission to clarify the identity or non-identity of the two minerals was unsuccessful because of the approximately simultaneous political changes in Germany during this period.

Due to the progress made in structural theory and in analytical technology, the Kleberite could be redefined by Ian Gray, Klaus Steinike and Colin M. MacRae with regard to its genesis. At the beginning of 2012 the mineral data and the chosen name were registered with the IMA / CNMNC under the register no. 2012-023 submitted for examination. In June of the same year it was finally recognized as an independent mineral and at the beginning of 2013 it was described as "Kleberite". With regard to the German history of kleberite, the hydroxyl pseudorutile from the Murray-Darling basin and that of Borneo ( Kalimantan ) became kleberite.

Type material of the Kleberite was found in the Museum für Naturkunde (Berlin) (type stage, location Königshain-Wiederau near Mittweida, Saxony / Germany, collection no. 1980-0283) and in the Museum Victoria in Melbourne (Australia) (co-type stages, sites Murray-Darling- Basin and Borneo , collection no. M52010 and M52011).

classification

Since Kleberite was only recognized as an independent mineral in 2013, it is not listed in the Strunz mineral system (8th edition), which has been outdated since 2001 . Only in the “Lapis mineral directory”, which was last updated in 2014, which, out of consideration for private collectors and institutional collections, is still based on the classic system of Karl Hugo Strunz , was the mineral given system no. IV / C.24-35 .

The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), classifies Kleberite in the expanded section of "Oxides with the molar ratio of metal: oxygen = 2: 3, 3: 5 and comparable" . This is further subdivided according to the relative size of the cations involved , so that the mineral can be found according to its composition in the sub-section “With medium-sized cations”, where it is the only member of the unnamed group 4.CB. forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns kleberite to the class of "oxides and hydroxides" and there in the department of "multiple oxides". Here he is to be found as the only member of the unnamed group 11/07/10 within the subsection “Multiple oxides as titanium oxides with [4] and [6] substitutions”.

Chemism

Analyzes on 15 Kleberite grains from Koenigshain showed contents of TiO 2 , Fe 2 O 3 , Al 2 O 3 , SiO 2 , P 2 O 5 , V 2 O 5 , MnO, MgO and H 2 O. The components of the titanate Matrix were separated from the foreign components (SiO 2 , Al 2 O 3 , P 2 O 5 , H 2 O) present in the nanopores . The secondary elements magnesium , manganese and vanadium come from the raw material ilmenite and are retained in the matrix structure. However, traces of manganese and vanadium are built in instead of magnesium and iron. The titanate matrix is ​​standardized to 6 Ti and 16 (O + OH) anions per formula unit in order to be consistent with the results of the crystal structure analysis, with a fixed O: OH ratio to maintain the charge balance.

For the Kleberit, the measured composition is Fe 3+ 1.01 Mg 0.06 Ti 6 O 11.2 (OH) 4.8 [Al 0.59 Si 0.31 P 0.04 O 1.60 · 1 , 8H 2 O], with the impurities from the nanopores being put in square brackets. This composition can be simplified as Fe 3+ Ti 4+ 6 O 11 (OH) 5 and requires 79.33% TiO 2 , 13.22% Fe 2 O 3, and 7.45% H 2 O.

Kleberites from Königshain, from the Australian Murray Basin and from Borneo (Kalimantan) have similar chemical compositions, with the exception of an unusually high aluminum content in the samples of Kalimantan, which can be traced back to diaspore crystals on the nanometer scale. The atomic ratio [Ti] / [Fe + Ti] varies between 0.8 and 0.9 in Kleberit.

Crystal structure

Kleberite crystallizes in the monoclinic crystal system in the space group P 2 1 / c (space group no. 14) with the lattice parameters a  = 7.537  Å ; b  = 4.5795 Å; c  = 9.885 Å and β = 131.02 °. Template: room group / 14

Kleberite, [Ti 4+ 3 □] [Ti 4+ 3 Fe 3+ ] O 11 (OH) 5 , is isotype (isostructural) to tivanite , [Ti 4+ 4 ] [V 3+ 4 ] O 12 (OH) 4 , meaning that it crystallizes with the same crystal structure as tivanite. In the Kleberite, Ti 4+ dominates on the M (2) metal atom position in contrast to Tivanite with V 3+ . In the related pseudorutile , [Ti 4+ 4 ] [(Fe 3+ , Ti 4+ ) 4 ] (O, OH) 16 , with Fe 3+ > Ti 4+ , Fe 3+ dominates in this position . The three isostructural minerals therefore differ mainly in the dominance of Ti 4+ , V 3+ or Fe 3+ on the M (2) position.

The crystal structure of the glueite can be described as an intergrowth of two structural elements in the size range of the unit cell. One element is the goethite type M (2) O (OH) (with M (2) = Ti), the other element is the rutile type M (1) O2. The intergrowth plane is parallel (100). On the (010) planes, the octahedra are linked via common edges and in this way form stepped chains according to [101]. The chains are connected by common corners along [010].

properties

morphology

Kleberite occurs in the form of rounded xenomorphic grains as well as idiomorphic crystals, the size of which usually varies between 0.040 mm and 0.3 mm. Seldom sizes of 0.5 mm are also achieved. Idiomorphic crystals with a rhombohedron as a supporting form, combined with the basic pinacoid , represent pseudomorphoses based on the trigonal ilmenite.

physical and chemical properties

The grains of the Kleberite are red-brown, while the color of the Kleberite from the Murray Basin and Borneo (Kalimantan) varies between red-brown and orange. The color intensity decreases as the iron content decreases. The line color of the glue is beige. The surfaces of the translucent grains have a wax to glass sheen, while fresh fractured surfaces show a semi-metallic diamond sheen , which also corresponds to the very high, zirconium-like values ​​for the light and double refraction of the adhesive .

In transmitted light, Kleberite is translucent, slightly cloudy and shows colors from yellow to red-brown to deep red. Thin splinters are transparent and red to yellow-brown. Characteristic is a very fine, agate-like rhythmic light-dark zonal structure, which is due to slight variations in the iron content (1 to 2% by weight). In reflected light, however, the mineral appears isotropic and dark blue-gray (similar to perovskite ). The reflectivity is very weak; brown internal reflections are rarely seen.

The mineral has good cleavage properties parallel and perpendicular to the c-axis [0001] of the former ilmenite grains, but because of its brittleness it breaks in a manner similar to amblygonite or prehnite , the fracture surfaces being uneven. With a Mohs hardness of 4 to 4.5, Kleberite is one of the medium-hard minerals that, like the reference mineral fluorite, can be easily scratched with a pocket knife. The measured density of the mineral is 3.28 g / cm³, its calculated density is 3.91 g / cm³. The difference between the measured and calculated density is due to the internal porosity of the grains with mean pore sizes of 18 nm. Due to their small size, these pores are not reached by the liquid when the density is determined in the pycnometer. They can also contain extremely fine-grain foreign minerals such as kaolinite , quartz or diaspore as well as remains of ilmenite, which explains the above-mentioned differences between measured and calculated density.

Kleberite in the form of the hydroxyl pseudorutile from the Murray Basin is slightly ferromagnetic.

Education and Locations

Kleberite forms as a secondary conversion product of magnesium-rich ilmenites and is found as an accessory component in the heavy mineral fraction of tertiary sands and gravels. Typical accompanying minerals in the heavy mineral concentrate are ilmenite, pseudorutile, leukoxene , representatives of the tourmaline group and representatives of the spinel group . Kaolinite, quartz and diaspore were found to be inclusions in the kleberite. Kleberite from Königshain and the other German deposits clearly emerged from the ilmenite that always accompanies it, very likely in the course of the innervolcanic gas / liquid / solid reaction processes of the basic tertiary volcanism along the Ore Mountain Abortion.

As a rare mineral formation, Kleberite could only be detected at a few sites, with around 50 sites being known to date (as of 2016). Type localities are Königshain near Mittweida in Saxony , Ilmenitsande in the Murray-Darling Basin in New South Wales , Australia , and the Indonesian part of the island of Borneo ( Kalimantan ).

Kleberite is known from at least 40 other sites in Oligocene and Miocene clastic sediments in an area at least 20,000 km² in size, bounded by the towns of Zwickau , Tharandt , Rietschen , Cottbus , Berlin , Bitterfeld and Zwickau in the federal states of Brandenburg , Saxony and Saxony-Anhalt ( State of knowledge until 1989), where it also forms a subordinate part of the heavy mineral fraction. Rough estimates indicated the presence of several thousand tons of kleberite. It is only enriched in the heavy mineral fraction at a few sites, for example in the Thierbach strata in the 63-315 μm grain fraction exposed in the Roda gravel pit ( coordinates of Roda / Frohburg ) not far from Frohburg in the Leipzig district in Saxony .

Locations in Switzerland and Austria are not known.

use

The beach soaps in the Australian Murray-Darling Basin, a global resource for rutile , zircon and ilmenite, contain up to 10% Kleberite ("Hydroxylian Pseudorutile") and are therefore an important source of raw materials for titanium. Kleberite has become stratigraphically in north-east Germany proven to be a “lead mineral”, with sparse distribution in the Oligocene and much greater distribution in the Miocene - here with relatively high contents in the Thierbach strata.

See also

literature

  • Ian E. Gray, Klaus Steinike, Colin M. MacRae (2013): Kleberite, Fe 3+ Ti 6 O 11 (OH) 5 , a new ilmenite alteration product, from Königshain, northeast Germany. In: Mineralogical Magazine , Volume 77 (1), pp. 45-55 doi : 10.1180 / minmag.2013.077.1.05
  • Ian E. Gray, Klaus Steinike: Kleberite, IMA 2012-023. CNMNC Newsletter No. 14 (October 2012), p. 1283, in: Mineralogical Magazine , Volume 76, pp. 1281–1288 ( PDF 93.2 kB )
  • Dieter Wolf, Hans Ulrich Thieke: On the history of mineralogy in the GDR. In: Series for Geosciences , Issue 18, 2011, pp. 7–31 (Kleberite: Chapter 2.2.1. Central Geological Institute Berlin; Chapter 4. First mineral descriptions).
  • Klaus Steinike: The history of the discovery of Kleberite in the northeastern part of Germany (1949–1990 territory of the GDR). In: Geohistor. Leaves, Berlin . Vol. 11, No. 1-2, Berlin 2008, ISSN  1436-3135 , pp. 113-128.
  • Klaus Steinike, Thomas Kaemmel: Kleberit - pseudorutile / hydroxyl pseudorutile - two worlds - two names - one mineral? In: Geohistorische Blätter . Vol. 11, No. 1-2, Berlin 2008, ISSN  1436-3135 , pp. 1-8.
  • Klaus Steinike, Georg Rohde, Hans-Joachim Bautsch: To the discovery of the mineral Kleberite. In: Mitteilungen der Deutsche Gesellschaft für Kristallographie eV , Issue 32 (2006), pp. 15-18. ( PDF 7.8 MB ; p. 11) Deutsche Gesellschaft für Kristallographie e. V.
  • Ian E. Gray, John A. Watts, Peter Bayliss: Mineralogical nomenclature: pseudorutile revalidated and neotype given. In: Mineralogical Magazine , Volume 58 (1994), pp. 597-600.
  • Max H. Hey: Thirty-first list of new mineral names. In: Mineralogical Magazine , Volume 43 (December 1980), pp. 1057-1069 ( PDF 1.15 MB ; Kleberite on p. 1062).
  • Michael Fleischer, George Y. Chao, Joseph A. Mandarino: New Mineral Names. In: American Mineralogist , Volume 64 (1979), pp. 652-659.
  • Hans-Joachim Bautsch, Georg Rohde, PA Sedlacek, A. Zedler: Kleberite - a new titanium-iron-oxide mineral from tertiary sands. In: Journal of Geological Sciences , Volume 6, Berlin 1978, pp. 661–671.
  • A. Zedler, PA Sedlacek, Georg Rohde, Hans-Joachim Bautsch: First results of the structure determination of a new mineral of the TiOx type. In: Journal of Geological Sciences , Volume 6, Berlin 1978, pp. 673-679.
  • Klaus Steinike: Report 1000.219 in the archive of the State Office for Geological Raw Materials Brandenburg ( parts of the report from March 14, 1963 and May 12, 1964).

Web links

Individual evidence

  1. ^ A b c d Ian E. Gray, C. Li: Hydroxylian pseudorutile derived from picroilmenite in the Murray Basin, southeastern Australia. In: Mineralogical Magazine , Volume 67 (2003), pp. 733-747.
  2. ↑ a b c d e f g h i j k l m n o p q r s t u Ian E. Gray, Klaus Steinike, Colin M. MacRae (2013): Kleberite, Fe 3+ Ti 6 O 11 (OH) 5 , a new ilmenite alteration product, from Königshain, northeast Germany. In: Mineralogical Magazine , Volume 77 (1), pp. 45-55 doi : 10.1180 / minmag.2013.077.1.05
  3. ↑ a b c d e f g h i j k l Klaus Steinike, Georg Rohde, Hans-Joachim Bautsch: To the discovery of the mineral Kleberite. In: Communications from the German Society for Crystallography eV , Issue 32 (2006), pp. 15–18, German Society for Crystallography e. V. ( PDF 7.8 MB ; p. 11)
  4. ↑ a b Hans-Joachim Bautsch, Georg Rohde, PA Sedlacek, A. Zedler: Kleberite - a new titanium-iron-oxide mineral from tertiary sands. In: Journal of Geological Sciences , Volume 6, Berlin 1978, pp. 661–671.
  5. ↑ a b Klaus Steinike, Thomas Kaemmel: Kleberit - Pseudorutil / Hydroxyl-Pseudorutil - two worlds - two names - one mineral? In: Geohistorische Blätter . Vol. 11, No. 1-2, Berlin 2008, ISSN  1436-3135 , pp. 1-8.
  6. ↑ a b c d Klaus Steinike: The history of the discovery of Kleberite in the north-eastern part of Germany (1949–1990 territory of the GDR). In: Geohistor. Leaves, Berlin . Vol. 11, No. 1-2, Berlin 2008, ISSN  1436-3135 , pp. 113-128.
  7. ^ A b Dieter Wolf, Hans Ulrich Thieke: On the history of mineralogy in the GDR. In: Series for Geosciences , Issue 18, 2011, pp. 7–31 (Kleberite: Chapter 2.2.1. Central Geological Institute Berlin; Chapter 4. First mineral descriptions).
  8. ↑ Michael Fleischer, George Y. Chao, Joseph A. Mandarino: New Mineral Names. In: American Mineralogist , Volume 64 (1979), pp. 652-659.
  9. ^ Ian E. Gray, John A. Watts, Peter Bayliss: Mineralogical nomenclature: pseudorutile revalidated and neotype given. In: Mineralogical Magazine , Volume 58 (1994), pp. 597-600.
  10. ^ Ian E. Gray, Klaus Steinike: Kleberite, IMA 2012-023. CNMNC Newsletter No. 14 (October 2012), p. 1283. In: Mineralogical Magazine , Volume 76, pp. 1281–1288 ( PDF 93.2 kB )
  11. ↑ Typmineral catalog Germany - storage of the Kleberit type material
  12. ↑ Stefan Weiß: New Minerals. In: Lapis , Volume 38 (Issue 6) (2013), p. 66.
  13. ↑ Mindat - Number of localities for Kleberite
  14. ↑ a b List of localities for Kleberite in the Mineralienatlas and Mindat