Thortveitite | |
---|---|
![]() 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 hardness | 5-6 |
Luster | vitreous |
Streak | gray |
Specific gravity | 3.3-3.8 |
Thortveitite is a rare 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. [1] [2] [3] [4]
A transparent gem quality example was found in 2004, and reported in "The Journal of Gemmology". [5]
Dysprosium is the chemical element with the symbol Dy and atomic number 66. It is a rare-earth element in the lanthanide series with a metallic silver luster. Dysprosium is never found in nature as a free element, though, like other lanthanides, it is found in various minerals, such as xenotime. Naturally occurring dysprosium is composed of seven isotopes, the most abundant of which is 164Dy.
Scandium is a chemical element with the symbol Sc and atomic number 21.
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Group 3 is the first group of transition metals in the periodic table. This group is closely related to the rare-earth elements. Although some controversy exists regarding the composition and placement of this group, it is generally agreed among those who study the matter that this group contains the four elements scandium (Sc), yttrium (Y), lutetium (Lu), and lawrencium (Lr). The group is also called the scandium group or scandium family after its lightest member.
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).
The history of the New England Patriots began when Boston business executive William "Billy" Sullivan and Sullivan Brother Printers, owned by Joseph Sullivan, were awarded the eighth and final franchise of the developing American Football League (AFL) on November 16, 1959.
Luminescence dating refers to a group of methods of determining how long ago mineral grains were last exposed to sunlight or sufficient heating. It is useful to geologists and archaeologists who want to know when such an event occurred. It uses various methods to stimulate and measure luminescence.
Ikaite is the mineral name for the hexahydrate of calcium carbonate, CaCO3·6H2O. Ikaite tends to form very steep or spiky pyramidal crystals, often radially arranged, of varied sizes from thumbnail size aggregates to gigantic salient spurs. It is only found in a metastable state and decomposes rapidly by losing most of its water content once removed from near-freezing water. This "melting mineral" is more commonly known through its pseudomorphs.
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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.
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Ixiolite is an accessory oxide mineral found in granitic pegmatites. It is an oxide with the general chemical formula (Ta,Nb,Sn,Mn,Fe)4O8 or (Ta,Mn,Nb)O2.
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).
Axinite-(Mg) is a borosilicate mineral of aluminum, calcium and magnesium of the axinite group, with magnesium as the dominant cation in the place of the structure that can also be occupied by iron and manganese. It was discovered in gem material from Merelani Hills, Lelatema Mts, Manyara Region, Tanzania, which is consequently its type locality. It was initially called magnesioaxinite, referring to its membership in the axinite group and the role of magnesium as the dominant cation. The International Mineralogical Association (IMA) later changed its name to axinite-(Mg). Occasionally it has been carved as a collection gem.
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Scandium perchlorate is an inorganic compound with the chemical formula Sc(ClO4)3.
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