The ferrierite group of

zeolite Zeolites are microporous, crystalline aluminosilicate materials commonly used as commercial adsorbents and catalysts. They mainly consist of silicon, aluminium, oxygen, and have the general formula ･y where is either a metal ion or H+. These ...

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ...

s (the FER structure) consists of three very similar species: ferrierite- Mg, ferrierite- Na, and ferrierite- K, based on the dominant

cation An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...

in the A location. ferrierite-Mg and ferrierite-K are

orthorhombic In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with ...

minerals and ferrierite-Na is monoclinic with highly variable cationic composition . Calcium and other ions are often also present. They are found in vitreous to pearly, often radiating, spherical aggregates of thin blade-shaped transparent to translucent crystals. Ferrierite typically occurs as an alteration mineral in

basalt Basalt (; ) is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon. More than 90% of a ...

ic rocks and in

tuff Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock ...

aceous sediments. In North America, it is found at Kamloops Lake, BC, Canada (the original

type locality Type locality may refer to: * Type locality (biology) * Type locality (geology) See also * Local (disambiguation) * Locality (disambiguation) {{disambiguation ...

) and Leavitt Lake, California. Ferrierite was named for Canadian geologist and mining engineer Walter Frederick Ferrier (1865–1950).

Synthetic ferrierite

Synthetic ferrierites have even greater cation variability and have important uses as commercial filters and ion-exchange beds. Ferrierite-H can be used as a

catalyst Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

in the chemical industry for the acid-catalyzed skeletal

isomerization In chemistry, isomerization or isomerisation is the process in which a molecule, polyatomic ion or molecular fragment is transformed into an isomer with a different chemical structure. Enolization is an example of isomerization, as is tautome ...

of n-butenes to

isobutene Isobutylene (or 2-methylpropene) is a hydrocarbon with the chemical formula . It is a four-carbon branched alkene (olefin), one of the four isomers of butylene. It is a colorless flammable gas, and is of considerable industrial value. Producti ...

, the raw material for production of methyl tert-butyl ether (

MTBE Methyl ''tertiary''-butyl ether (MTBE), also known as methyl tert-butyl ether and ''tert''-butyl methyl ether, is an organic compound with a structural formula (CH3)3COCH3. MTBE is a volatile, flammable, and colorless liquid that is sparingly sol ...

). The hydrophobic all-silica ferrierite (Si-FER) has very high selectivity in the separation of alcohol–water mixtures, due to the very restrictive shape and space constraints of the FER framework type. At high pressure, Si-FER can achieve the separation of an ethanol–water liquid mixture into supramolecular blocks of its components, namely, ethanol dimer wires and water tetramer squares.

References

External links

Structure type FER
Sodium minerals Potassium minerals Aluminium minerals Magnesium minerals Zeolites Orthorhombic minerals Minerals in space group 71 {{silicate-mineral-stub