Yuksporite is a rare

inosilicate Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust. In mineralogy, silica (silicon dioxide, ) is usually consid ...

mineral with double width, unbranched chains, and the complicated

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbol ...

. It contains the relatively rare elements strontium,

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 niobium, as well as the commoner metallic elements

potassium Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmosph ...

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar t ...

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...

and

manganese Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...

. As with all silicates, it contains groups of linked

silicon Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic ta ...

and

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as ...

atoms, as well as some associated

water molecules Water () is a polar inorganic compound that is at room temperature a tasteless and odorless liquid, which is nearly colorless apart from an inherent hint of blue. It is by far the most studied chemical compound and is described as the "un ...

. Yuksporite is a member of the umbite group that has just two known members, umbite, , and yuksporite. It was first reported in 1922, from

nepheline syenite Nepheline syenite is a holocrystalline plutonic rock that consists largely of nepheline and alkali feldspar. The rocks are mostly pale colored, grey or pink, and in general appearance they are not unlike granites, but dark green varieties are al ...

occurrences in the

Kola Peninsula sjd, Куэлнэгк нёа̄ррк , image_name= Kola peninsula.png , image_caption= Kola Peninsula as a part of Murmansk Oblast , image_size= 300px , image_alt= , map_image= Murmansk in Russia.svg , map_caption = Location of Murmansk Oblas ...

, Russia, and named by

Alexander Fersman Alexander Evgenyevich Fersman (; 8 November 1883 – 20 May 1945) was a prominent Soviet Russian geochemist and mineralogist, and a member of the Soviet Academy of Sciences (1919–1945). Early life and education Fersman was born in St. Peter ...

for the locality, near Mount Yukspor.

Unit cell

Yuksporite was originally thought to be orthorhombic,

space group In mathematics, physics and chemistry, a space group is the symmetry group of an object in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of an object that leave it uncha ...

unknown. In 2004, however, the structure was solved using synchrotron radiation and found to be

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 ...

2/m with

P2₁/m. The monoclinic

unit cell In geometry, biology, mineralogy and solid state physics, a unit cell is a repeating unit formed by the vectors spanning the points of a lattice. Despite its suggestive name, the unit cell (unlike a unit vector, for example) does not necessaril ...

has two formula units per cell (Z = 2) and side lengths a = 7.126 Å, b = 24.913 Å and c = 17.075 Å, with the angle β between the a and c axes equal to 101.89°.Krivovichev, Yakovenchuk, Armbruster, Dobelin, Pattison, Weber and Depmeier (2004) American Mineralogist 89:1561

Appearance

The mineral is brownish pink, rose pink or yellowish in color, with a silky to vitreous luster and a nearly white streak. It occurs in semi-transparent fibrous, scaly or lamellar aggregates up to 10 cm across.

Properties

Yuksporite is a

biaxial In crystal optics, the index ellipsoid (also known as the ''optical indicatrix'' or sometimes as the ''dielectric ellipsoid'') is a geometric construction which concisely represents the refractive index, refractive indices and as ...

mineral, but most authors do not specify whether it is (+) or (-); the Handbook of Mineralogy gives it as (+). All agree, however, that the

refractive indices In optics, the refractive index (or refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability of that medium. The refractive index determines how much the path of light is bent, or ...

are N_x = 1.644 and N_z = 1.660 (with N_y unspecified), which are larger than those for

quartz Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical ...

, but similar to those for

tourmaline Tourmaline ( ) is a crystalline silicate mineral group in which boron is compounded with elements such as aluminium, iron, magnesium, sodium, lithium, or potassium. Tourmaline is a gemstone and can be found in a wide variety of colors. The te ...

. Yuksporite shows

pleochroism Pleochroism (from Greek πλέων, ''pléōn'', "more" and χρῶμα, ''khrôma'', "color") is an optical phenomenon in which a substance has different colors when observed at different angles, especially with polarized light. Backgrou ...

, with X pale rose-yellow, and Y, Z rose-yellow. It has a

hardness In materials science, hardness (antonym: softness) is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion. In general, different materials differ in their hardness; for example hard ...

of to 5, between

fluorite Fluorite (also called fluorspar) is the mineral form of calcium fluoride, CaF2. It belongs to the halide minerals. It crystallizes in isometric cubic habit, although octahedral and more complex isometric forms are not uncommon. The Mohs sca ...

and apatite, and

specific gravity Relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water at its densest ...

3.05, similar to fluorite. It exhibits barely detectable radioactivity.

Occurrence and associations

The type locality is the Hackman Valley, Yukspor Mt,

Khibiny Massif The Khibiny Mountains (russian: Хиби́ны ; sjd, Umptek) is one of the two main mountain ranges of the Kola Peninsula, Russia, within the Arctic Circle, located between Imandra and Umbozero lakes. The range is also known as Khibiny Massif, ...

, Murmanskaja Oblast', Northern Region, Russia, and

type material In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes t ...

is conserved at the

Fersman Mineralogical Museum ) , native_name = , native_name_lang = , logo = , logo_upright = , logo_alt = , logo_caption = , image = Fersman Mineralogical Museum.JPG , image_upright = , a ...

, Academy of Sciences, Moscow, Russia, catalogue number 25847. The only occurrences reported by Mindat.org are in Russia. At the Khibiny massif it occurs in veins in nepheline syenite associated with

titanite Titanite, or sphene (from the Greek ''sphenos'' (σφηνώ), meaning wedge), is a calcium titanium nesosilicate mineral, Ca Ti Si O5. Trace impurities of iron and aluminium are typically present. Also commonly present are rare earth metals ...

pectolite Pectolite is a white to gray mineral, Na Ca2 Si3 O8(O H), sodium calcium hydroxide inosilicate. It crystallizes in the triclinic system typically occurring in radiated or fibrous crystalline masses. It has a Mohs hardness of 4.5 to 5 and a specif ...

astrophyllite Astrophyllite is a very rare, brown to golden-yellow hydrous potassium iron titanium silicate mineral. Belonging to the astrophyllite group, astrophyllite may be classed either as an inosilicate, phyllosilicate, or an intermediate between th ...

, biotite and

aegirine Aegirine is a member of the clino pyroxene group of inosilicate minerals. Aegirine is the sodium endmember of the aegirine-augite series. Aegirine has the chemical formula Na Fe Si2 O6 in which the iron is present as Fe3+. In the aegirine-augit ...

. At the

Murun Massif Murun (russian: Мурун) is a mountain in the Olyokma-Chara Plateau, at the border of Irkutsk Oblast and Yakutia, Russian Federation. Geography A high summit is the highest point of the Murun Massif in the Olyokma-Chara Plateau, part of th ...

in the Sakha Republic it is associated with aegirine,

kalsilite Kalsilite ( K Al Si O4) is a vitreous white to grey feldspathoidal mineral that is found in some potassium-rich lavas, such as from Chamengo Crater in Uganda. It has a relative hardness In materials science, hardness (antonym: softness) is a ...

, potassic

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 ...

, titanite,

lamprophyllite Lamprophyllite (named for its lustrous cleavage) is a rare, but widespread mineral Ti-silicate mineral usually found in intrusive agpasitic igneous rocks. Yellow, reddish brown, Vitreous, Pearly. Lamprophyllite formula is (Sr,Ba,K,Na)2Na(Na,Fe, ...

, wadeite and tausonite.

References

External links

View molecule
in

Jmol Jmol is computer software for molecular modelling chemical structures in 3-dimensions. Jmol returns a 3D representation of a molecule that may be used as a teaching tool, or for research e.g., in chemistry and biochemistry. It is written in the ...

{{commons category, Yuksporite Inosilicates Potassium minerals Strontium minerals Manganese minerals Monoclinic minerals Minerals in space group 10