Thortveitite

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Thortveitite
Thortveitite-ea14a.jpg
Thortveitite
General
Category Mineral
Formula
(repeating unit)
(Sc,Y)2Si2O7
Strunz classification 9.BC.05
Crystal system Monoclinic
Crystal class Prismatic (2/m)
(same H-M symbol)
Space group C2/m
Identification
Mohs scale hardness5-6
Luster vitreous
Streak gray
Specific gravity 3.3-3.8

Thortveitite is a mineral consisting of scandium yttrium silicate (Sc,Y)2Si2O7. It is the primary source of scandium. Occurrence is in granitic pegmatites. It was named after Olaus Thortveit, a Norwegian engineer. It is grayish-green, black or gray in color.

A transparent gem quality example was found in 2004, and reported in "The Journal of Gemmology", 2008 Volume 31.

The mineral is actually a uniform mixture of oxides of silicon, scandium, and yttrium. It isn't a true compound in itself.

See also

Related Research Articles

Erbium Chemical element with atomic number 68

Erbium is a chemical element with the symbol Er and atomic number 68. A silvery-white solid metal when artificially isolated, natural erbium is always found in chemical combination with other elements. It is a lanthanide, a rare earth element, originally found in the gadolinite mine in Ytterby in Sweden, from which it got its name.

Holmium Chemical element with atomic number 67

Holmium is a chemical element with the symbol Ho and atomic number 67. Part of the lanthanide series, holmium is a rare-earth element.

Lanthanum Chemical element with atomic number 57

Lanthanum is a chemical element with the symbol La and atomic number 57. It is a soft, ductile, silvery-white metal that tarnishes slowly when exposed to air and is soft enough to be cut with a knife. It is the eponym of the lanthanide series, a group of 15 similar elements between lanthanum and lutetium in the periodic table, of which lanthanum is the first and the prototype. It is also sometimes considered the first element of the 6th-period transition metals, which would put it in group 3, although lutetium is sometimes placed in this position instead. Lanthanum is traditionally counted among the rare earth elements. The usual oxidation state is +3. Lanthanum has no biological role in humans but is essential to some bacteria. It is not particularly toxic to humans but does show some antimicrobial activity.

Scandium Chemical element with atomic number 21

Scandium is a chemical element with the symbol Sc and atomic number 21. A silvery-white metallic d-block element, it has historically been classified as a rare-earth element, together with yttrium and the lanthanides. It was discovered in 1879 by spectral analysis of the minerals euxenite and gadolinite from Scandinavia.

Thulium Chemical element with atomic number 69

Thulium is a chemical element with the symbol Tm and atomic number 69. It is the thirteenth and third-last element in the lanthanide series. Like the other lanthanides, the most common oxidation state is +3, seen in its oxide, halides and other compounds; because it occurs so late in the series, however, the +2 oxidation state is also stabilized by the nearly full 4f shell that results. In aqueous solution, like compounds of other late lanthanides, soluble thulium compounds form coordination complexes with nine water molecules.

Ytterby

Ytterby is a village on the Swedish island of Resarö, in Vaxholm Municipality in the Stockholm archipelago. Today the residential area is dominated by suburban homes.

Rare-earth element Any of the fifteen lanthanides plus scandium and yttrium

The rare-earth elements, also called the rare-earth metals or rare-earth oxides, or the lanthanides are a set of 17 nearly indistinguishable lustrous silvery-white soft heavy metals. Scandium and yttrium are considered rare-earth elements because they tend to occur in the same ore deposits as the lanthanides and exhibit similar chemical properties, but have different electronic and magnetic properties.

The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical behaviour begins to repeat, meaning that elements with similar behaviour fall into the same vertical columns. The fifth period contains 18 elements, beginning with rubidium and ending with xenon. As a rule, period 5 elements fill their 5s shells first, then their 4d, and 5p shells, in that order; however, there are exceptions, such as rhodium.

Gadolinite

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)
2
FeBe
2
Si
2
O
10
. It is called gadolinite-(Ce) or gadolinite-(Y), depending on the prominent composing element. 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.

Group 3 element

Group 3 is a group of elements in the periodic table. This group, like other d-block groups, should contain four elements, but it is not agreed what elements belong in the group. Scandium (Sc) and yttrium (Y) are always included; the spaces below yttrium are either occupied by lanthanum (La) and actinium (Ac), or by lutetium (Lu) and lawrencium (Lr), with the former option more common. Less frequently, it is considered the group should be expanded to 32 elements or bifurcated to include both La-Ac and Lu-Lr. When the group is understood to contain all of the lanthanides, it subsumes the rare earth metals. Yttrium, and less frequently scandium, are sometimes also counted as rare-earth metals.

Yttrium(III) oxide

Yttrium oxide, also known as yttria, is Y2O3. It is an air-stable, white solid substance.

Scandium oxide

Scandium(III) oxide or scandia is a inorganic compound with formula Sc2O3. It is one of several oxides of rare earth elements with a high melting point. It is used in the preparation of other scandium compounds as well as in high-temperature systems (for its resistance to heat and thermal shock), electronic ceramics, and glass composition (as a helper material).

Scandium fluoride

Scandium(III) fluoride, ScF3, is an ionic compound. It is slightly soluble in water but dissolves in the presence of excess fluoride to form the ScF63− anion.

Organoyttrium chemistry is the study of compounds containing carbon-yttrium bonds. They are studied in academic research, but have not received widespread use otherwise. These compounds use YCl
3
as a starting material, which is in turn obtained in a reaction of Y
2
O
3
with concentrated hydrochloric acid and ammonium chloride.

Yttrium nitride

Yttrium nitride, YN, is a nitride of yttrium.

Yttrium Chemical element with atomic number 39

Yttrium is a chemical element with the symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a "rare-earth element". Yttrium is almost always found in combination with lanthanide elements in rare-earth minerals, and is never found in nature as a free element. 89Y is the only stable isotope, and the only isotope found in the Earth's crust.

Allendeite, Sc4Zr3O12, is an oxide mineral. Allendeite was discovered in a small ultrarefractory inclusion within the Allende meteorite. This inclusion has been named ACM-1. It is one of several scandium rich minerals that have been found in meteorites. Allendeite is trigonal, with a calculated density of 4.84 g/cm3. The new mineral was found along with hexamolybdenum. These minerals, are believed to demonstrate conditions during the early stages of the Solar System, as is the case with many CV3 carbonaceous chondrites such as the Allende meteorite. It is named after the Allende meteorite that fell in 1969 near Pueblito de Allende, Chihuahua, Mexico.

Scandiobabingtonite was first discovered in the Montecatini granite quarry near Baveno, Italy in a pegmatite cavity. Though found in pegmatites, the crystals of scandiobabingtonite are sub-millimeter sized, and are tabular shaped. Scandiobabingtonite was the sixth naturally occurring mineral discovered with the rare earth element scandium, and grows around babingtonite, with which it is isostructural, hence the namesake. It is also referred to as scandian babingtonite. The ideal chemical formula for scandiobabingtonite is Ca2(Fe2+,Mn)ScSi5O14(OH).

Pyrosilicate

A pyrosilicate is a type of chemical compound; either an ionic compound that contains the pyrosilicate anionSi
2
O6−
7
, or an organic compound with the hexavalent ≡O
3
Si
-O-SiO
3
≡ group. The anion is also called disilicate or diorthosilicate.

Scandium(III) hydroxide is an inorganic compound with the chemical formula Sc(OH)3. It is an amphoteric compound. It is slightly soluble in water, and its saturated solution (pH = 7.85) contains Sc(OH)3 and a small amount of Sc(OH)2+. The solubility of scandium(III) hydroxide in water is 0.0279 mol/L. It will convert to ScO(OH) after aging, greatly reducing the solubility (0.0008 mol/L). Scandium(III) hydroxide can be produced by reacting scandium salts and alkali hydroxides. In the reaction, different starting ingredients can generate different intermediates such as Sc(OH)1.75Cl1.25, Sc(OH)2NO3 and Sc(OH)2.32(SO4)0.34.

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