Colimaite
Encyclopedia
Colimaite, the naturally occurring analog of synthetic K3VS4, is a sulfide mineral discovered in southwestern Mexico
. The potassium
-vanadium
sulfide
was collected from the crater of the Colima volcano. The mineral Colimaite is named after the locality of this volcano and has been approved in 2007, along with its mineral name, by the Commission on New Minerals, Nomenclature and Classification (CNMNC). It has been given the International Mineralogical Association
number of IMA 2007-045.
has been calculated as (K2.95,Na0.06)Σ3.01V1.03S3.97. The enrichment of vanadium in Colima’s volcanic gases make it unique. The study of sulfur
content in the fumaroles is also important, in order to know how an eruption could affect global climate due to SO2 emissions.
making it orthorhombic. The vanadium and sulfur atoms form tetrahedra. Potassium ions separate these tetrahedra in two different ways. In one case, the potassium ion is bound to five sulfur atoms at an average distance of 3.296 Å with an additional two sulfur atoms at a distance of 3.771 Å. In the other case, the potassium ion is bound to eight sulfur atoms at an average distance of 3.314 Å. In both cases, the potassium ions are in an irregular coordination polyhedron.
–like particles due to the acicular
habit of extremely fine needles forming the aggregates. The size of these aggregates range from 10 to 100 µm. The needles themselves have been measured up to 50 µm in length and 20 µm in width. Although colimaite belongs to the orthorhombic crystal class, their crystallographic forms were not observed. The particles were regular parallelepipeds and elongated rectangular prisms
. The color of colimaite is dark golden and opaque. The streak is a yellow green with a resinous to greasy luster. It is non-fluorescent
. It is brittle with no observed cleavage and a splintery fracture. Because of grain size, the hardness and density could not be measured but the density has been calculated to 2.235 g/cm3.
, arcanite
, thenardite
, baryte and native gold have been collected from the fumaroles of this volcano. Although minerals were collected at temperatures from 400 °C to 800 °C, colimaite was assembled in a more narrow temperature interval of 450 °C - 600 °C. There are similarities between the volcanic gases of the Colima crater and the gases of other volcanoes, but there are some differences that make Colima unique. Notable differences are the vanadium, zinc
and copper
enrichment of the Colima gases. These same gases also lack cadmium
and molybdenum
bearing minerals.
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. The potassium
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...
-vanadium
Vanadium
Vanadium is a chemical element with the symbol V and atomic number 23. It is a hard, silvery gray, ductile and malleable transition metal. The formation of an oxide layer stabilizes the metal against oxidation. The element is found only in chemically combined form in nature...
sulfide
Sulfide
A sulfide is an anion of sulfur in its lowest oxidation state of 2-. Sulfide is also a slightly archaic term for thioethers, a common type of organosulfur compound that are well known for their bad odors.- Properties :...
was collected from the crater of the Colima volcano. The mineral Colimaite is named after the locality of this volcano and has been approved in 2007, along with its mineral name, by the Commission on New Minerals, Nomenclature and Classification (CNMNC). It has been given the International Mineralogical Association
International Mineralogical Association
The International Mineralogical Association is an international group of 38 national societies. The goal is to promote the science of mineralogy and to standardize the nomenclature of the 4000 plus known mineral species...
number of IMA 2007-045.
Composition
The chemical formula of Colimaite is K3VS4. It’s empirical formulaEmpirical formula
In chemistry, the empirical formula of a chemical compound is the simplest positive integer ratio of atoms of each element present in a compound. An empirical formula makes no reference to isomerism, structure, or absolute number of atoms. The empirical formula is used as standard for most ionic...
has been calculated as (K2.95,Na0.06)Σ3.01V1.03S3.97. The enrichment of vanadium in Colima’s volcanic gases make it unique. The study of sulfur
Sulfur
Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
content in the fumaroles is also important, in order to know how an eruption could affect global climate due to SO2 emissions.
Structure
Colimaite exhibits the Pnma (P 21/n 21/m 21/a) 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...
making it orthorhombic. The vanadium and sulfur atoms form tetrahedra. Potassium ions separate these tetrahedra in two different ways. In one case, the potassium ion is bound to five sulfur atoms at an average distance of 3.296 Å with an additional two sulfur atoms at a distance of 3.771 Å. In the other case, the potassium ion is bound to eight sulfur atoms at an average distance of 3.314 Å. In both cases, the potassium ions are in an irregular coordination polyhedron.
Physical Properties
The formations of colimaite have been described as hedgehogHedgehog
A hedgehog is any of the spiny mammals of the subfamily Erinaceinae and the order Erinaceomorpha. There are 17 species of hedgehog in five genera, found through parts of Europe, Asia, Africa, and New Zealand . There are no hedgehogs native to Australia, and no living species native to the Americas...
–like particles due to the acicular
Crystal habit
Crystal habit is an overall description of the visible external shape of a mineral. This description can apply to an individual crystal or an assembly of crystals or aggregates....
habit of extremely fine needles forming the aggregates. The size of these aggregates range from 10 to 100 µm. The needles themselves have been measured up to 50 µm in length and 20 µm in width. Although colimaite belongs to the orthorhombic crystal class, their crystallographic forms were not observed. The particles were regular parallelepipeds and elongated rectangular prisms
Prism (geometry)
In geometry, a prism is a polyhedron with an n-sided polygonal base, a translated copy , and n other faces joining corresponding sides of the two bases. All cross-sections parallel to the base faces are the same. Prisms are named for their base, so a prism with a pentagonal base is called a...
. The color of colimaite is dark golden and opaque. The streak is a yellow green with a resinous to greasy luster. It is non-fluorescent
Fluorescence
Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation of a different wavelength. It is a form of luminescence. In most cases, emitted light has a longer wavelength, and therefore lower energy, than the absorbed radiation...
. It is brittle with no observed cleavage and a splintery fracture. Because of grain size, the hardness and density could not be measured but the density has been calculated to 2.235 g/cm3.
Geological Occurrence
Colimaite occurs as a sublimate from the volcanic fumaroles of the Colima volcano in Mexico. Other minerals including cristobaliteCristobalite
The mineral cristobalite is a high-temperature polymorph of silica, meaning that it has the same chemical formula, SiO2, but a distinct crystal structure. Both quartz and cristobalite are polymorphs with all the members of the quartz group which also include coesite, tridymite and stishovite...
, arcanite
Arcanite
Arcanite is a potassium sulfate mineral with formula: K2SO4.Arcanite was first described in 1845 for an occurrence in old pine railroad ties in the Santa Ana tin mine, Trabuco Canyon, Santa Ana Mountains, Orange County, California, USA...
, thenardite
Thenardite
Thenardite is an anhydrous sodium sulfate mineral, Na2SO4 which occurs in arid evaporite environments. It also occurs in dry caves and old mine workings as an efflorescence and as a crusty deposit around fumaroles. It occurs in volcanic caves on Mt...
, baryte and native gold have been collected from the fumaroles of this volcano. Although minerals were collected at temperatures from 400 °C to 800 °C, colimaite was assembled in a more narrow temperature interval of 450 °C - 600 °C. There are similarities between the volcanic gases of the Colima crater and the gases of other volcanoes, but there are some differences that make Colima unique. Notable differences are the vanadium, zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
and copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
enrichment of the Colima gases. These same gases also lack cadmium
Cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Similar to zinc, it prefers oxidation state +2 in most of its compounds and similar to mercury it shows a low...
and molybdenum
Molybdenum
Molybdenum , is a Group 6 chemical element with the symbol Mo and atomic number 42. The name is from Neo-Latin Molybdaenum, from Ancient Greek , meaning lead, itself proposed as a loanword from Anatolian Luvian and Lydian languages, since its ores were confused with lead ores...
bearing minerals.