Samarskite-(Y)
- Samarskite
Samarskite - (Y), also referred as Samarskite or known among the synonymous names Adelfolit, Adelpholit, Ampangabéit and Nüvit, is a rarely occurring mineral from the mineral class of " oxides and hydroxides ". It crystallizes in the orthorhombic crystal system with the chemical composition (Y, Fe 3 , U4 ) ( Nb, Ta) O4 and usually develops just massive, massive mineral aggregates, but rarely also tabular to prismatic crystals of jet black color with dark brown stroke color.
The mineral is opaque in thin layers but translucent. Coarse crystalline Samarskite - (Y ) shows glass to waxy luster, massive aggragate, however, are dull.
Special Features
The mineral is classified as very highly radioactive due to its uranium content of up to 15.9% and has a specific activity of about 28.74 kBq / g (compared to natural potassium 31.2 Bq / g).
Etymology and history
The mineral was named after its discoverer, the Russian Vasily Montanists Ewgrafowitsch Samarskij - Bychowez (1803-1870), who worked in the Corps of the Russian Mining Engineers ( 1861-1870 boss). The mineral name was given in 1847 at the suggestion of the German mineralogist Heinrich Rose. For Samarskite the names Uranotantal are (after Gustav Rose) and Yttroilmenit uses ( RI Herman) in the older literature. As a type locality (shaft No. 50) applies the pit " Blyumovskaya " on the mountain Ilmen in " Ilmen nature reserve " in the Russian Chelyabinsk Oblast ( southern Urals ).
For the scientific study of lanthanoid mineral Samarskite an important position occurs. The relatively large available quantities of this mineral permitted a comprehensive analysis. Marc Delafontaine discovered in 1878 with the spectral analysis of the heterogeneity of the obtained from him Didymoxides. Lecoq de Boisbaudran isolated in 1879 from Samarskite the samarium. Marignac could also extract the gadolinium from him in 1880 in addition to samarium.
Classification
In the now outdated but still in use 8th edition of the mineral classification by Strunz the Samarskite - (Y) belonged to the general ward of the " oxide with the molar ratio of metal: oxygen = 1: 2 ( MO2 and related compounds ) ", where he, together with Calciosamarskit, euxenite ( Y) Fersmit, Ishikawait, Loranskit - (Y) Písekit - (Y) Polycrase (Y ), samarskite - (Yb), Tanteuxenit - (Y) Uranopolykras, Yttrocolumbit - (Y) Yttrokrasit ( Y) and Yttrotantalit (Y ), the " euxenite - series" with the system number. IV/D.19 formed.
The valid since 2001 and used by the IMA 9th edition of the Strunz'schen Mineral classification assigns the Samarskite - (Y ) is also in the department of " oxides with the molar ratio of metal: oxygen = 1: 2 (and similar ) " a. However, this is now precisely divided by the size of the involved cations and the crystal structure, so that the mineral according to its structural chemical structure in the subdivision "With medium-sized cations: chains of edge-sharing octahedra " is to find where it, along with Ashanit, Calciosamarskit, Ishikawait Ixiolit, Písekit - (Y), samarskite - (Yb ), and Srilankit Yttrocolumbit - (Y) the " samarskite group " with the system no. 4.DB.25 forms.
The classification of minerals according to Dana assigns the Samarskite - (Y ) is also in the class of " oxides ", There, however, in the department of " multiple oxides with Nb, Ta and Ti ". Here he is with samarskite - (Yb ) in the " Samarskite group " with the system no. 08:01:11 found within the sub-division of " multiple oxides with Nb, Ta and Ti with the formula ABO4 ".
Education and Locations
Samarskite - (Y) forms as a rare accessory ingredient in granite pegmatite dykes with a high proportion of rare earth metals.
In paragenesis, where he occurs among others, albite, eschynite, beryl, biotite, columbite, garnet, magnetite, monazite, muscovite, topaz, tourmaline, zircon and uraninite.
At the site of the first discovery, Bljumowskaja kop ' in southern Illmengebirge ( at Miass ), the Samarskite was found in adhesions with columbite. The Illmengebirge is a part of the Southern Urals and is located approximately 200 km south of Yekaterinburg. The Bljumowskaja pit ( Bljumowskaja kop ') in 1835 and is known as a rich mineral reserves in the Southern Urals. Here in 1911 were recovered about 15 kg Samarskite by the radium expedition of Miterabeitern Vernadsky's and passed for examination by Marie Skłodowska- Curie.
As a rather rare mineral formation can Samarskite - (Y) indeed be in different localities partly abundant, but overall he is not widespread. Worldwide, so far (as of 2012) about 350 localities known as. Apart from its type locality pit " Blyumovskaya " was the mineral still be found in other places on the mountain Ilmen and the nearby river Miass in the Urals, as well as at two points in the Fund East Siberian Republic of Buryatia.
In Germany there was Samarskite - (Y) among others Matzersdorf and supporters village in the municipality Tittling and Haden village in the municipality Waidhaus in Bavaria as well as at several locations in the Eifel near Niedermendig and on Krufter oven.
In Austria, the mineral previously occurred only in the scheelite deposit in Felbental ( Hohe Tauern ) in Salzburg and Mitter riding / Aigen in Mühlkreisautobahn in Upper Austria. Another locality, Meitschenhof in the community Pregarten is not yet confirmed.
The only known locality for Samarskite - (Y ) in Switzerland is an abandoned Granophyr - quarry near the Chapel of the Madonna in the Ticino community Carona TI.
Other localities lie including Australia, Brazil, China, Finland, France, Guyana, India, Italy, Japan, Canada, Madagascar, Mozambique, Norway, Poland, Romania, Zambia, Saudi Arabia, Sweden, Slovakia, South Africa, Czech Republic, Ukraine and in several states of the USA.
Crystal structure
Samarskite - (Y ) crystallizes in the orthorhombic space group Pbcn ( Raumgruppen-Nr. 60) with the lattice parameters a = 4.92 Å; b = 5.69 Å and c = 5.21 Å and two formula units per unit cell.
Use
Samarskite serves as raw material for the extraction of lanthanide metals as well as for the rare transition metals niobium and tantalum.