Ilmenite

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Ilmenite
Ilmenite-173863.jpg
Ilmenite crystals from Poudrette quarry, Mont Saint-Hilaire , Rouville , Montérégie , Québec, Canada
General and classification
other names
  • Menaccanite
  • Titanium iron
chemical formula FeTiO 3
Mineral class
(and possibly department)
Oxides with metal: oxygen = 2: 3
System no. to Strunz
and to Dana
4.CB.05 ( 8th edition : IV / C.05)
04.03.05.01
Similar minerals Magnetite
Crystallographic Data
Crystal system trigonal
Crystal class ; symbol trigonal-rhombohedral; 3
Space group R 3 (No. 148)Template: room group / 148
Lattice parameters a  = 5.09  Å ; c  = 14.09 Å
Formula units Z  = 6
Twinning lamellar according to {0001} or {101 1 }
Physical Properties
Mohs hardness 5 to 6
Density (g / cm 3 ) 4.5 to 5
Cleavage no
Break ; Tenacity shell-like, uneven
colour black, steel gray
Line color black
transparency opaque
shine Metal gloss, matt
magnetism slightly magnetic
Crystal optics
Optical character uniaxial negative
Pleochroism Reflective pleochroism: strong - ω = brownish pink, ε = dark brown

Ilmenite , also known as titanium iron , titanium iron ore or by its synonym menaccanite , is a frequently occurring mineral from the mineral class of " oxides and hydroxides ". It crystallizes in the trigonal crystal system with the chemical composition FeTiO 3 and develops mostly thick tabular crystals , but also granular to massive aggregates in black to steel-gray color and black line color .

Ilmenite is formally a mixture with a proportion of 48% iron (II) oxide and 52% titanium dioxide and looks very similar to magnetite . It is often contaminated by admixtures of hematite , with which mixed crystals form at high temperatures.

Etymology and history

The mineral was first discovered in the Menaccan Valley in Cornwall (England) and described in 1791 by William Gregor . It was initially named after its place of discovery as menaccanite (also menachanite , menakanite or menakan ).

The final name of ilmenite received the mineral in 1827 by Adolph Theodor Kupffer (1799-1865), who after the analysis of the mountain Ilmen in Ilmengebirge noted originating in the southern Urals Minerals that this no Titanit was, as anticipated, but a new connection.

classification

In the meanwhile outdated, but still in use 8th edition of the mineral classification according to Strunz , the ilmenite belonged to the mineral class of "oxides and hydroxides" and there to the department of "oxides with the molar ratio of metal: oxygen = 2: 3", where he named the "Ilmenite group" with the system no. IV / C.05 and the other members Akimotoit , Brizziit , Ecandrewsit , Geikielith , Melanostibit and Pyrophanit .

The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), assigns ilmenite to the class of "oxides and hydroxides" and there in the expanded section of "oxides with the molar ratio of metal: oxygen = 2: 3, 3: 5 and comparable “. However, this section is further subdivided according to the 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 can be found together with auroantimonate , brizziite, corundum , ecandrewsite, eskolaite , geikielite, hematite , Karelianite , melanostibite, pyrophanite and romanite the "corundum group" with the system no. 4.CB.05 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns ilmenite to the class of "oxides and hydroxides" and there in the category of "oxides". Here he is the namesake of the "Ilmenit Group" with the system no. 04.03.05 and the other members Geikielith, Pyrophanit, Ecundrewsit, Melanostibit, Brizziit-III and Akimotoit can be found within the subdivision of " Simple oxides with a cation charge of 3+ (A 2 O 3 ) ".

Crystal structure

Crystal structure of ilmenite

Ilmenite crystallizes trigonal in the space group R 3 (space group no. 148) with the lattice parameters a  = 5.09  Å and c  = 14.09 Å and 6 formula units per unit cell . Template: room group / 148

Modifications and varieties

Iserin is an ilmenite variety that was first found in the form of loose, unrolled grains on the Iserwiese near the municipality of Jizerka in the Czech Republic.

Education and Locations

Ilmenitrose from the Buckwheat mine near Franklin, New Jersey , USA
Ilmenite, cassiterite and smoky quartz from the Erongo Mountains in Namibia

Ilmenite occurs as a component of igneous rocks such as gabbro and diorite , sometimes also in quartz veins and occasionally in metamorphic rocks . As a weather-resistant mineral, it is deposited in river sands together with magnetite and rutile as so-called soap .

Ilmenite is very often the predominant titanium phase in amphibolites because its stability field extends up to very high temperatures. The mineral rutile is found at higher pressures .

Ilmenite has already been proven to be a frequent mineral formation in many places, with over 5000 sites known so far (as of 2017). In addition to its locality on Mount Ilmen , the mineral occurred in Russia in many other places in Siberia , the Far Eastern Republic , in the northern Caucasus , in northwestern Russia and in the Urals .

Among other things, Girardville in the Canadian province of Québec , where ilmenite crystals up to 15 cm in size were discovered, is worth mentioning due to the extraordinary finds of ilmenite. Crystals up to 12 cm in size appeared in the Norwegian communities of Arendal and Kragerö . Hauge i Dalane , also located in Norway, is also one of the most important deposits in Europe.
From Miass in the Urals crystal finds of 10 cm in size were known and the Swiss Maderanertal is known for its ilmenite crystals in rosette shape similar to the
hematite roses . Ilmenitroses can also be found at other sites such as B. in the Buckwheat pit near Franklin, New Jersey in the United States (USA).

In Germany the mineral was among others in the Black Forest , at the Kaiserstuhl , in Kraichgau and in the Odenwald in Baden-Württemberg; in the Fichtel Mountains , in the Swabian-Franconian Forest Mountains , in the Spessart , in the Bavarian Forest and the Upper Palatinate in Bavaria; in the Odenwald and on the Vogelsberg in Hesse; near Cuxhaven , Güntersen and Bad Harzburg in Lower Saxony; in the Siebengebirge in North Rhine-Westphalia; in the Eifel in Rhineland-Palatinate; near Orscholz and Eisen / Nohfelden in Saarland; in the Ore Mountains , Upper Lusatia and Vogtland in Saxony; found near Barmstedt and Niendorf / Lübeck-Moisling in Schleswig-Holstein as well as near Gera and in the Thuringian Forest in Thuringia.

In Austria, Ilmenite was found on Pauliberg and in the Oberwart district in Burgenland; in many places in Carinthia and Styria ; in the Mostviertel , in the Waldviertel and near Spitz in Lower Austria; in many places in the Hohe Tauern in Salzburg; in north and east Tyrol as well as near Schärding and Plöcking in Upper Austria.

In Switzerland, apart from Maderanertal, the mineral was found in several places in the cantons of Graubünden , Ticino and Valais as well as in Gadmertal and the municipality of Guttannen in the canton of Bern, near Entlebuch in the canton of Lucerne.

Other sites are found in Afghanistan , Egypt , Algeria , Angola , eastern Antarctica , Argentina , Armenia , Ethiopia , Australia , Bangladesh , Belgium , Bolivia , Botswana , Brazil , Bulgaria , Burkina Faso , Chile , China , Ecuador , Fiji , Finland , France , French Guiana , French Polynesia , the French Antilles island of Martinique , Gabon , Ghana , Greece , Greenland , Guatemala , Guinea , Honduras , India , Indonesia , Iran , Ireland , Israel , Italy , Japan , Cambodia , Cameroon , Canada , Jersey Channel Island , Kazakhstan , Kenya , Colombia , the Democratic Republic of the Congo , Korea , Cuba , Lesotho , Libya , Madagascar , Malawi , Malaysia , Morocco , Mauritania , North Macedonia , Mexico , Mongolia , Montserrat , Myanmar , Namibia , Nepal , New Zealand , Nigeria , Oman , Pakistan , Panama , Papua New Guinea , Paraguay , Peru , Poland , Portugal , Romania , Zambia , Sweden , Zimbabwe , Slovakia , Slovenia , Spain , South Africa , Sri Lanka , Suriname , Swaziland , Taiwan , Tajikistan , Tanzania , Thailand , Chad , Czech Republic , Turkey , Uganda , Ukraine , Hungary , Uzbekistan , Venezuela , and the United Kingdom (Great Britain), the United States of America (USA) and Vietnam .

Ilmenite could also be detected in rock samples from the Mid-Atlantic Ridge , the Southwest Indian Ridge and the southern California coast as well as off Earth on the moon near the landing bases of Apollo 11 , 14 and 17 as well as Luna 16 and 20 .

use

Ilmenite ore, ground and polished

Ilmenite is the most important titanium mineral. In 2011, around 47% of global demand for titanium dioxide production was covered by ilmenite. Two thirds of the total annual production of this metal comes from Canada , Australia and South Africa .

Scientists working with geologist James B. Garvin from the Goddard Space Flight Center suspect that ilmenite also occurs in significant quantities on the moon , and hope to use it there to produce oxygen for a possible lunar base. Infrared images taken by the Hubble Space Telescope in 2005 in the lunar region around the Aristarchus crater show strong evidence of larger ilmenite deposits.

Ilmenite is one of the main raw materials for the production of titanium dioxide using both the chloride process and the sulfate process .

See also

literature

  • AT Kupffer: Ilmenite, a new fossil (including new varieties of zircon and gadolinite) from Siberia . In: Karl Wilhelm Gottlob Kastner (Ed.): Archive for the entire study of nature . Nuremberg 1827, p. 1–13 ( rruff.info [PDF; 451 kB ]).
  • Martin Okrusch, Siegfried Matthes: Mineralogy. An introduction to special mineralogy, petrology and geology . 7th fully revised and updated edition. Springer Verlag, Berlin et al. 2005, ISBN 3-540-23812-3 , pp. 54 .

Web links

Commons : Ilmenite  - collection of images, videos and audio files

Individual evidence

  1. a b c d e Hugo Strunz , Ernest H. Nickel : Strunz Mineralogical Tables. Chemical-structural Mineral Classification System . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p.  193 .
  2. Mindat - Ilmenite (English)
  3. Hans Lüschen: The names of the stones. The mineral kingdom in the mirror of language . Ott Verlag, Thun and Munich 1968, p. 332 (titanium) .
  4. AT Kupffer: Ilmenite, a new fossil (including new varieties of zircon and gadolinite) from Siberia . In: Karl Wilhelm Gottlob Kastner (Ed.): Archive for the entire study of nature . Nuremberg 1827, p. 1–13 ( rruff.info [PDF; 451 kB ]).
  5. ^ Friedrich Klockmann : Klockmanns textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke , Stuttgart 1978, ISBN 3-432-82986-8 , pp.  517 (first edition: 1891).
  6. Mindat - Number of localities for Ilmenite
  7. Petr Korbel, Milan Novák: Mineral Encyclopedia (=  Dörfler Natur ). Nebel Verlag, Eggolsheim 2002, ISBN 978-3-89555-076-8 , p. 84 .
  8. a b List of locations for Ilmenite in the Mineralienatlas and in Mindat - Localities for Ilmenite
  9. 70017 Ilmenite Basalt curator.jsc.nasa.gov, pdf. Retrieved November 25, 2011
  10. Titanium dioxide market study, Ceresana, February 2013
  11. J. Winkler; Titanium dioxide; Vincentz Networl; 2003