Ixiolite is an accessory oxide mineral found in granitic pegmatites. It is an oxide with the general chemical formula or .

Structure

Ixiolite was originally reported as crystallizing in the

monoclinic In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in the orthorhombic s ...

crystal system In crystallography, a crystal system is a set of point groups (a group of geometric symmetries with at least one fixed point). A lattice system is a set of Bravais lattices. Space groups are classified into crystal systems according to their poin ...

. Detailed studies of the scandium, tin and titanium rich varieties indicate that they form crystals in the orthorhombic system whereas tungsten ixiolite is monoclinic.

Discovery and occurrence

It was first described in 1857 for an occurrence at Skogsböle, Kimito Island,

Finland Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...

. The name is for ''Ixion'', the

Greek mythological A major branch of classical mythology, Greek mythology is the body of myths originally told by the ancient Greeks, and a genre of Ancient Greek folklore. These stories concern the origin and nature of the world, the lives and activities of d ...

character related to ''Tantalus,'' as the mineral contains

tantalum Tantalum is a chemical element with the symbol Ta and atomic number 73. Previously known as ''tantalium'', it is named after Tantalus, a villain in Greek mythology. Tantalum is a very hard, ductile, lustrous, blue-gray transition metal that ...

. Ixiolite is typically associated with

feldspar Feldspars are a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the ''plagioclase'' (sodium-calcium) felds ...

tapiolite Tapiolite Fe,_manganese.html"_;"title="iron.html"_;"title="iron">Fe,_manganese">Mn)( Nb,_tantalum.html"_;"title="manganese">Mn)(niobium.html"_;"title="iron">Fe,_manganese.html"_;"title="iron.html"_;"title="iron">Fe,_manganese">Mn)(niobium">Nb,_tan ...

, cassiterite,

microlite Microlite was once known as a pale-yellow, reddish-brown, or black isometric mineral composed of sodium calcium tantalum oxide with a small amount of fluorine. Its chemical formula is. Today it is a name of a group of oxide minerals of a similar ...

, and

rutile Rutile is an oxide mineral composed of titanium dioxide (TiO2), the most common natural form of TiO2. Rarer polymorphs of TiO2 are known, including anatase, akaogiite, and brookite. Rutile has one of the highest refractive indices at visib ...

Substitution and varieties

Trace elements include

zirconium Zirconium is a chemical element with the symbol Zr and atomic number 40. The name ''zirconium'' is taken from the name of the mineral zircon, the most important source of zirconium. The word is related to Persian '' zargun'' (zircon; ''zar-gun'' ...

hafnium Hafnium is a chemical element with the symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in many zirconium minerals. Its existence was predicted by Dmitri M ...

titanium Titanium is a chemical element with the Symbol (chemistry), symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resista ...

and

tungsten Tungsten, or wolfram, is a chemical element with the symbol W and atomic number 74. Tungsten is a rare metal found naturally on Earth almost exclusively as compounds with other elements. It was identified as a new element in 1781 and first isol ...

. As with other tantalum and niobium bearing minerals considerable substitution and a number of varieties exist. Substitutions in the formula are common and the varieties stannian ixiolite (

tin Tin is a chemical element with the symbol Sn (from la, stannum) and atomic number 50. Tin is a silvery-coloured metal. Tin is soft enough to be cut with little force and a bar of tin can be bent by hand with little effort. When bent, t ...

), titanian ixiolite (titanium) and wolframian ixiolite (tungsten) have been reported.

Scandium Scandium is a chemical element with the symbol Sc and atomic number 21. It is a silvery-white metallic d-block element. Historically, it has been classified as a rare-earth element, together with yttrium and the Lanthanides. It was discovered in ...

is present in many ixiolite sample with percentages up to 4.0 percent Sc₂O₃, but usually less than one percent scandium oxide. High scandium ixiolites, containing from 4 to 19% scandium oxide are typically also rich in tin and titanium.

Economic importance

Ixiolite together with

tantalite The mineral group tantalite Fe,_manganese.html"_;"title="iron.html"_;"title="iron">Fe,_manganese">Mn)Tantalum">Ta2oxygen.html" ;"title="manganese">Mn)Tantalum.html" ;"title="iron">Fe,_manganese.html" ;"title="iron.html" ;"title="iron">Fe, manga ...

wodginite Wodginite is a manganese, tin, tantalum oxide mineral with the chemical formula . It may also include significant amounts of niobium. Background Wodginite was first described in 1963 for an occurrence in the Wodgina pegmatite, Wodgina, Pilbara Re ...

are the most important minerals mined for the element

. Ixiolite contains about 69 % tantalum oxide (Ta₂O₅) and is a common constituent of

coltan Coltan (short for columbite–tantalites and known industrially as tantalite) is a dull black metallic ore from which the elements niobium and tantalum are extracted. The niobium-dominant mineral in coltan is columbite (after niobium's original ...

ore.

References

{{Reflist Oxide minerals Orthorhombic minerals Minerals in space group 60

Structure

Discovery and occurrence

Substitution and varieties

Economic importance

Further reading

References