.mw-parser-output .hidden-begin{box-sizing:border-box;width:100%;padding:5px;border:none;font-size:95%}.mw-parser-output .hidden-title{font-weight:bold;line-height:1.6;text-align:left}.mw-parser-output .hidden-content{text-align:left}You can help expand this article with text translated from the corresponding article in German. (January 2024) Click [show] for important translation instructions. Machine translation, like DeepL or Google Translate, is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text into the English Wikipedia. Consider adding a topic to this template: there are already 8,987 articles in the main category, and specifying|topic= will aid in categorization. Do not translate text that appears unreliable or low-quality. If possible, verify the text with references provided in the foreign-language article. You must provide copyright attribution in the edit summary accompanying your translation by providing an interlanguage link to the source of your translation. A model attribution edit summary is Content in this edit is translated from the existing German Wikipedia article at [[:de:Gadolinit]]; see its history for attribution. You should also add the template ((Translated|de|Gadolinit)) to the talk page. For more guidance, see Wikipedia:Translation.
Gadolinite
Gadolinite (black portion at top)
General
CategoryNesosilicate
Formula
(repeating unit)
(Ce,La,Nd,Y)2FeBe2Si2O10
IMA symbolGad[1]
Strunz classification9.AJ.20
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupP21/n

Gadolinite, sometimes known as ytterbite, is a silicate mineral consisting principally of the silicates of cerium, lanthanum, neodymium, yttrium, beryllium, and iron with the formula (Ce,La,Nd,Y)2FeBe2Si2O10. It is called gadolinite-(Ce) or gadolinite-(Y), depending on the prominent composing element (Y if yttrium predominates, and Ce if cerium). It may contain 35.5% yttria sub-group rare earths, 2.2% ceria earths, as much as to 11.6% BeO, and traces of thorium. It is found in Sweden, Norway, and the US (Texas and Colorado).

Characteristics

Gadolinite is fairly rare and typically occurs as well-formed crystals. It is nearly black in color and has a vitreous luster. The hardness is between 6.5 and 7 on the Mohs scale, and the specific gravity is between 4.0 and 4.7. It fractures in a conchoidal pattern and streaks grayish-green. It was also thought to exhibit pyrognomic properties, as it can emit visible light when heated to relatively low temperatures, but the scientific consensus is that this is the product of thermoluminescence.[2][3]

Name and discovery

Gadolinite was named in 1800 for Johan Gadolin, the Finnish mineralogist-chemist who first isolated an oxide of the rare-earth element yttrium from the mineral in 1792. The rare earth gadolinium was also named after him. However, gadolinite does not contain more than trace amounts of gadolinium. When Gadolin analyzed this mineral, he missed an opportunity to discover a second element: the element he thought was aluminium (alumina) was in fact beryllium (beryllia), an element that was not officially identified until 1798.

Several elements were discovered as a consequence of lengthy analysis and decomposition of the ore gadolinite.[citation needed] As the ore was progressively analysed, the residue was first given the label ceria, then lanthana, and subsequently yttria, erbia, and terbia. In order of date discovered, the list of elements includes cerium, lanthanum, erbium, terbium, yttrium, ytterbium, holmium, thulium, scandium, praseodymium, neodymium and dysprosium. Several of these new elements were either discovered or isolated by Carl Gustaf Mosander in the 1830s and 1840s.

Uses

Gadolinite and euxenite are quite abundant and are future sources of yttrium sub group rare earths. At present, these elements are recovered from monazite concentrates (after recovery of ceria sub-group metals).

See also

References

  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ Frondel, Clifford (1958). "Systematic mineralogy of uranium and thorium". U.S. Geological Survey Bulletin. 1064. doi:10.3133/b1064.
  3. ^ Schwartz K., Lang M. (2016) Mineral Defects. In: White W. (eds) Encyclopedia of Geochemistry. Encyclopedia of Earth Sciences Series. Springer, Cham

Further reading