Lorandite
Encyclopedia
Lorandite is a thallium
arsenic
sulfosalt with the chemical formula: TlAsS2. Though rare, it is the most common thallium-bearing mineral. Lorandite occurs in low-temperature hydrothermal associations and in gold
and mercury
ore
deposits. Associated minerals include stibnite
, realgar
, orpiment
, cinnabar
, vrbaite, greigite
, marcasite
, pyrite
, tetrahedrite
, antimonian sphalerite
, arsenic
and barite
.
The mineral is being used for detection of solar neutrino
via a certain nuclear reaction
involving thallium. It has a monoclinic crystal structure consisting of spiral chains of AsS3 tetrahedra interconnected by thallium atoms, and can be synthesized in the laboratory.
, near Kavadarci
, Macedonia
in 1894 and named after Loránd Eötvös
, a prominent Hungarian physicist
.
and at the Beshtau
uranium deposit, near Pyatigorsk
, northern Caucasus Mountains
, Russia. As an ore mineral, it is encountered at the Lanmuchang Hg–Tl deposit, Guizhou Province, China; at the Zarshuran gold deposit in northeastern Iran
; and at the Lengenbach Quarry
in Switzerland
. In the US, it is present at the New Rambler Cu–Ni mine in Wyoming; at the Jerritt Canyon mines, Independence Mountains district and Carlin Gold mine in Nevada; and at the Mercury-gold deposit in Utah.
. The mixture is placed in an autoclave
and is kept at elevated temperature (~250 °C) for several days. This procedure yields deep-red prismatic crystals elongated along the [001] crystal axis, which are similar to the mineral in appearance and crystallographic structure details.
P21/a, Z = 4, with the lattice constants a = 1.228 nm, b = 1.130 nm, c = 0.6101 nm and β = 104.5 °. It consists of spiral chains of AsS3 tetrahedra oriented to the [010] crystal axis. The chains are covalently interlinked by irregularly coordinated Tl atoms (chain interconnections not shown in the picture), and breaking of these links is responsible for crystal cleavage.
. The method relies on the 205Tl(νe,e–)205 reaction which has a relatively low threshold energy of 52 keV
and thus relatively high efficiency. This reaction yields 205Pb isotope which has a long lifetime of 15.4 million years; it is induced not only by neutrinos, but also by other cosmic particles. They all have different penetration depth in the Earth crust, and thus analysis of the 205Pb content in a thallium-containing ore taken from different depths brings information on the neutrinos of the past millennia. Thus, the LORandite EXperiment (LOREX), is running between 2008 and 2010 and is based in one of the largest source of lorandite, the Allchar deposit
in southern Macedonia
.
Thallium
Thallium is a chemical element with the symbol Tl and atomic number 81. This soft gray poor metal resembles tin but discolors when exposed to air. The two chemists William Crookes and Claude-Auguste Lamy discovered thallium independently in 1861 by the newly developed method of flame spectroscopy...
arsenic
Arsenic
Arsenic is a chemical element with the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250.Arsenic is a metalloid...
sulfosalt with the chemical formula: TlAsS2. Though rare, it is the most common thallium-bearing mineral. Lorandite occurs in low-temperature hydrothermal associations and in gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
and mercury
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...
ore
Ore
An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....
deposits. Associated minerals include stibnite
Stibnite
Stibnite, sometimes called antimonite, is a sulfide mineral with the formula Sb2S3. This soft grey material crystallizes in an orthorhombic space group. It is the most important source for the metalloid antimony...
, realgar
Realgar
Realgar, α-As4S4, is an arsenic sulfide mineral, also known as "ruby sulphur" or "ruby of arsenic". It is a soft, sectile mineral occurring in monoclinic crystals, or in granular, compact, or powdery form, often in association with the related mineral, orpiment . It is orange-red in colour, melts...
, orpiment
Orpiment
Orpiment, As2S3, is a common monoclinic arsenic sulfide mineral. It has a Mohs hardness of 1.5 to 2 and a specific gravity of 3.46. It melts at 300 °C to 325 °C...
, cinnabar
Cinnabar
Cinnabar or cinnabarite , is the common ore of mercury.-Word origin:The name comes from κινναβαρι , a Greek word most likely applied by Theophrastus to several distinct substances...
, vrbaite, greigite
Greigite
Greigite is an iron sulfide mineral with formula Fe3S4. It is the sulfur equivalent of the iron oxide magnetite . It was first described in 1964 for an occurrence in San Bernardino County, California, and named after the mineralogist and physical chemist Joseph W...
, marcasite
Marcasite
The mineral marcasite, sometimes called white iron pyrite, is iron sulfide with orthorhombic crystal structure. It is physically and crystallographically distinct from pyrite, which is iron sulfide with cubic crystal structure. Both structures do have in common that they contain the disulfide...
, pyrite
Pyrite
The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...
, tetrahedrite
Tetrahedrite
Tetrahedrite is a copper antimony sulfosalt mineral with formula: 12Sb4S13. It is the antimony endmember of the continuous solid solution series with arsenic bearing tennantite. Pure endmembers of the series are seldom if ever seen in nature. Of the two, the antimony rich phase is more common...
, antimonian sphalerite
Sphalerite
Sphalerite is a mineral that is the chief ore of zinc. It consists largely of zinc sulfide in crystalline form but almost always contains variable iron. When iron content is high it is an opaque black variety, marmatite. It is usually found in association with galena, pyrite, and other sulfides...
, arsenic
Arsenic
Arsenic is a chemical element with the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250.Arsenic is a metalloid...
and barite
Barite
Baryte, or barite, is a mineral consisting of barium sulfate. The baryte group consists of baryte, celestine, anglesite and anhydrite. Baryte itself is generally white or colorless, and is the main source of barium...
.
The mineral is being used for detection of solar neutrino
Solar neutrino
Electron neutrinos are produced in the Sun as a product of nuclear fusion. By far the largest fraction of neutrinos passing through the Earth are Solar neutrinos....
via a certain nuclear reaction
Nuclear reaction
In nuclear physics and nuclear chemistry, a nuclear reaction is semantically considered to be the process in which two nuclei, or else a nucleus of an atom and a subatomic particle from outside the atom, collide to produce products different from the initial particles...
involving thallium. It has a monoclinic crystal structure consisting of spiral chains of AsS3 tetrahedra interconnected by thallium atoms, and can be synthesized in the laboratory.
History
Lorandite was first discovered at the Allchar depositAllchar deposit
Allchar deposit is a low-temperature hydrothermal gold–arsenic–antimony–thallium deposit in southern Macedonia. For some time, the thallium-rich part of the deposit was mined. The Crven Dol mine yielded thallium and the ore body still holds estimated amount of 500 t of thallium...
, near Kavadarci
Kavadarci
Kavadarci is a town located in the Tikveš region of the Republic of Macedonia. Situated in the heart of Macedonia’s wine country, it is home to the largest winery in south-eastern Europe, named after the Tikveš plain. The town of Kavadarci is the seat of Kavadarci Municipality...
, Macedonia
Republic of Macedonia
Macedonia , officially the Republic of Macedonia , is a country located in the central Balkan peninsula in Southeast Europe. It is one of the successor states of the former Yugoslavia, from which it declared independence in 1991...
in 1894 and named after Loránd Eötvös
Loránd Eötvös
Baron Loránd Eötvös de Vásárosnamény , more commonly called Baron Roland von Eötvös in English literature, was a Hungarian physicist. He is remembered today largely for his work on gravitation and surface tension.-Life:...
, a prominent Hungarian physicist
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
.
Distribution
Apart from the Allchar deposit in Macedonia, lorandite is also found at the Dzhizhikrut Sb–Hg deposit in TajikistanTajikistan
Tajikistan , officially the Republic of Tajikistan , is a mountainous landlocked country in Central Asia. Afghanistan borders it to the south, Uzbekistan to the west, Kyrgyzstan to the north, and China to the east....
and at the Beshtau
Beshtau
Beshtau is an isolated five-domed igneous mountain near Pyatigorsk in the Northern Caucasus....
uranium deposit, near Pyatigorsk
Pyatigorsk
Pyatigorsk is a city in Stavropol Krai on the Podkumok River, about from Mineralnye Vody. Since January 19, 2010 it has been the administrative center of the North Caucasian Federal District of Russia...
, northern Caucasus Mountains
Caucasus Mountains
The Caucasus Mountains is a mountain system in Eurasia between the Black Sea and the Caspian Sea in the Caucasus region .The Caucasus Mountains includes:* the Greater Caucasus Mountain Range and* the Lesser Caucasus Mountains....
, Russia. As an ore mineral, it is encountered at the Lanmuchang Hg–Tl deposit, Guizhou Province, China; at the Zarshuran gold deposit in northeastern Iran
Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...
; and at the Lengenbach Quarry
Lengenbach Quarry
The Lengenbach Quarry is located in the Binn Valley and it is noted among the mineralogical community for its unusual sulfosalt specimens.-Location:...
in Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
. In the US, it is present at the New Rambler Cu–Ni mine in Wyoming; at the Jerritt Canyon mines, Independence Mountains district and Carlin Gold mine in Nevada; and at the Mercury-gold deposit in Utah.
Laboratory synthesis
Single crystals of lorandite can be grown from a mixture of thallium nitrate (TlNO3), elemental arsenic and sulfur in concentrated aqueous solution of ammoniaAmmonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...
. The mixture is placed in an autoclave
Autoclave
An autoclave is an instrument used to sterilize equipment and supplies by subjecting them to high pressure saturated steam at 121 °C for around 15–20 minutes depending on the size of the load and the contents. It was invented by Charles Chamberland in 1879, although a precursor known as the...
and is kept at elevated temperature (~250 °C) for several days. This procedure yields deep-red prismatic crystals elongated along the [001] crystal axis, which are similar to the mineral in appearance and crystallographic structure details.
Crystal structure
The crystal structure of lorandite is monoclinic, space groupSpace group
In mathematics and geometry, a space group is a symmetry group, usually for three dimensions, that divides space into discrete repeatable domains.In three dimensions, there are 219 unique types, or counted as 230 if chiral copies are considered distinct...
P21/a, Z = 4, with the lattice constants a = 1.228 nm, b = 1.130 nm, c = 0.6101 nm and β = 104.5 °. It consists of spiral chains of AsS3 tetrahedra oriented to the [010] crystal axis. The chains are covalently interlinked by irregularly coordinated Tl atoms (chain interconnections not shown in the picture), and breaking of these links is responsible for crystal cleavage.
Applications
In 1976, it was proposed to use a thallium-rich mineral, lorandite, for detection of solar neutrinoSolar neutrino
Electron neutrinos are produced in the Sun as a product of nuclear fusion. By far the largest fraction of neutrinos passing through the Earth are Solar neutrinos....
. The method relies on the 205Tl(νe,e–)205 reaction which has a relatively low threshold energy of 52 keV
Kev
Kev can refer to:*Kev Hawkins, a fictional character.*Kevin, a given name occasionally shortened to "Kev".*Kiloelectronvolt, a unit of energy who symbol is "KeV".* Krefelder Eislauf-VereinKEV can refer to:...
and thus relatively high efficiency. This reaction yields 205Pb isotope which has a long lifetime of 15.4 million years; it is induced not only by neutrinos, but also by other cosmic particles. They all have different penetration depth in the Earth crust, and thus analysis of the 205Pb content in a thallium-containing ore taken from different depths brings information on the neutrinos of the past millennia. Thus, the LORandite EXperiment (LOREX), is running between 2008 and 2010 and is based in one of the largest source of lorandite, the Allchar deposit
Allchar deposit
Allchar deposit is a low-temperature hydrothermal gold–arsenic–antimony–thallium deposit in southern Macedonia. For some time, the thallium-rich part of the deposit was mined. The Crven Dol mine yielded thallium and the ore body still holds estimated amount of 500 t of thallium...
in southern Macedonia
Republic of Macedonia
Macedonia , officially the Republic of Macedonia , is a country located in the central Balkan peninsula in Southeast Europe. It is one of the successor states of the former Yugoslavia, from which it declared independence in 1991...
.