Phyllosilicates

upright=1.3|thumb|Bentonite layers from an ancient deposit of weathering|weathered [[volcanic ash tuff in Wyoming]] thumb|Gray shale and bentonites (Benton Shale; Colorado Springs, Colorado)

Chrysocolla ( ) is a hydrous copper phyllosilicate mineral and mineraloid with the formula (x&nbsp;<&nbsp;1) or .

upright=1.35|thumb|Samples of soapstone

Sepiolite, also known in English by the German name meerschaum ( , ; ; meaning "sea foam"), is a soft white clay mineral, often used to make tobacco pipes (known as meerschaum pipes). A complex magnesium silicate, a typical chemical formula for which is Mg4Si6O15(OH)2·6H2O, it can be present in fibrous, fine-particulate, and solid forms.

Allophane is an amorphous to poorly crystalline hydrous aluminium silicate clay mineraloid. Its chemical formula is Al2O3·(SiO2)1.3-2·(2.5-3)H2O. Since it has short-range atomic order, it is a mineraloid, rather than a mineral, and can be identified by its distinctive infrared spectrum and its X-ray diffraction pattern. It was first described in 1816 in Gräfenthal, Thuringia, Germany. Allophane is a weathering or hydrothermal alteration product of volcanic glass and feldspars and sometimes has a composition similar to kaolinite but generally has a molar ratio of Al:Si = 2. It typically forms u

Cavansite, named for its chemical composition of calcium vanadium silicate, is a deep blue hydrous calcium vanadium phyllosilicate mineral, occurring as a secondary mineral in basaltic and andesitic rocks along with a variety of zeolite minerals. Its blue coloring comes from vanadium, a metal ion. Discovered in 1967 in Malheur County, Oregon, cavansite is a relatively rare mineral. It is polymorphic with the even rarer mineral, pentagonite. It is most frequently found in Pune, India, and in the Deccan Traps, a large igneous province.

Neptunite is a silicate mineral with the formula KNa2Li(Fe2+, Mn2+)2Ti2Si8O24. With increasing manganese it forms a series with mangan-neptunite. is the variety with vanadium replacing the titanium in the formula.

Okenite (CaSi2O5·2H2O) is a silicate mineral that is usually associated with zeolites. It most commonly is found as small white "cotton ball" formations within basalt geodes. These formations are clusters of straight, radiating, fibrous crystals that are both bendable and fragile. It also belongs to the family of the calcium silicate hydrates (C-S-H) commonly found in hardened cement paste. In cement chemist notation (CCN) it is noted as CaO·2SiO2·2H2O and abbreviated as CS2H2.

Ekanite is an uncommon silicate mineral with chemical formula or . It is a member of the steacyite group. It is among the few gemstones that are naturally radioactive. Most ekanite is mined in Sri Lanka, although deposits also occur in Russia and North America. Clear and well-colored stones are rare as the radioactivity tends to degrade the crystal matrix over time in a process known as metamictization.

thumb|Scanning electron microscope (SEM) photograph of smectite clay – magnification 23,500 – [[U.S. Geological Survey – Tuckup Canyon]] thumb|Typical cracks pattern of a smectite-rich bentonite after its desiccation and shrinkage

Gyrolite, NaCa16(Si23Al)O60(OH)8·14H2O, is a rare silicate mineral (basic sodium calcium silicate hydrate: N-C-S-H, in cement chemist notation) belonging to the class of phyllosilicates. Gyrolite is also often associated with zeolites. It is most commonly found as spherical or radial formations in hydrothermally altered basalt and basaltic tuffs. These formations can be glassy, dull or fibrous in appearance.

Carletonite is a rare phyllosilicate mineral with formula KNa4Ca4(CO3)4Si8O18(F,OH)·(H2O). Its tetragonal crystals are a translucent blue, white, colorless or pink with a vitreous to dull lustre. It has a density of 2.45 and a hardness of 4–4.5.

Pentagonite is a rare phyllosilicate mineral with formula Ca(VO)Si4O10·4H2O. Its characteristic blue color is due to the presence of the vanadyl () cation in its crystal lattice. The oxidation state of vanadium in the vanadyl cation is +4; therefore, it is a divalent cation. It was named for the unusual twinning called a fiveling with an apparent five-fold symmetry. It is a dimorph of cavansite.

Ajoite () is a hydrated sodium potassium copper aluminium silicate hydroxide mineral. Ajoite has the chemical formula (Na,K)Cu7AlSi9O24(OH)6·3H2O, and minor Mn, Fe and Ca are usually also present in the structure. Ajoite is used as a minor ore of copper.

Hisingerite is an iron(III) phyllosilicate mineral with formula . A black or dark brown, lustrous secondary mineral, it is formed by the weathering or hydrothermal alteration of other iron silicate and sulfide minerals.

Bannisterite is a phyllosilicate mineral named in honor of mineralogist and x-ray crystallographer Dr. Frederick Allen Bannister (1901–1970). It is chemically similar to tamaite, a calcium-dominant member of the ganophyllite group. It was previously identified as ganophyllite in 1936, but it is more structurally related to the stilpnomelane group. It was approved by the IMA in 1967.

Macdonaldite is a rare barium silicate mineral with a chemical formula of BaCa4Si16O36(OH)2·10H2O. Macdonaldite was first described in 1965 and named for Gordon A. Macdonald (1911–1978) an American volcanologist at the University of Hawaii.

Ussingite is a silicate mineral with formula Na2AlSi3O8(OH).

Chapmanite is a rare silicate mineral belonging to the phyllosilicate group, discovered in 1924, and named in honour of the late Edward John Chapman (1821–1904), a geology professor at the University of Toronto. Chemically, it is an iron antimony silicate, closely related to bismutoferrite, and may contain aluminium impurities. It is closely associated with silver mines, most notably the Keeley mine in Ontario, Canada, found in quartz veinlets containing graphite in gneiss. It takes the form of a powdery, yellow-green, semitransparent solid, and leaves a streak of the same color. Early German

Imogolite is an aluminium silicate clay mineral with the chemical formula . It occurs in soils formed from volcanic ash and was first described in 1962 for an occurrence in Uemura, Kumamoto prefecture, Kyushu Region, Japan. Its name originates from the Japanese word , which refers to the brownish yellow soil derived from volcanic ash. It occurs together with allophane, quartz, cristobalite, gibbsite, vermiculite and limonite.

smoking pipe made from the mineral sepiolite

Armstrongite (CaZr[Si6O15]·3H2O) is a silicate mineral.

Searlesite is a sodium borosilicate mineral, with the chemical formula NaBSi2O5(OH)2. It was discovered in 1914 at Searles Lake, California, and was named to honor John W. Searles (16 November 1828 – 7 October 1897), California pioneer, who drilled the well that yielded the first known Searlesite.

Sanbornite is a rare barium phyllosilicate mineral with formula BaSi2O5. Sanbornite is a colorless to white to pale green, platey orthorhombic mineral with Mohs hardness of 5 and a specific gravity of 3.74.

Kegelite is a complex silicate mineral with formula Pb8Al4Si8O20(SO4)2(CO3)4(OH)8.

Zakharovite is a mineral, a silicate of sodium and manganese; formula Na4Mn5Si10O24(OH)6·6H2O. It has a yellow colour with a pearly lustre. Discovered in 1982 in the Kola peninsula of Northern Russia, it is named after Evgeny Evgenevich Zakharov (1902–1980), the director of the Moscow Institute of Geological Exploration.

Falcondoite, a member of the sepiolite group, was first discovered in the Dominican Republic, near the town of Bonao. The mineral was found in a deposit mined by Falconbridge Dominica, and so was named "falcondoite" after the company. Falcondoite is frequently associated with sepiolite, garnierite, talc, and serpentine, and is commonly nickel-bearing. While the chemical formula for falcondoite can vary, the mineral must contain more nickel than magnesium to be considered its own species. The ideal chemical formula for falcondoite is (Ni,Mg)4Si6O15(OH)2·6H2O.

chemical compound

Nelenite is a rare manganese iron phyllosilicate arsenate mineral found in Franklin Furnace, New Jersey.

Magadiite is a hydrous sodium silicate mineral (NaSi7O13(OH)3·4(H2O)) which precipitates from alkali brines as an evaporite phase. It forms as soft (Mohs hardness of 2) white powdery monoclinic crystal masses. The mineral is unstable and decomposes during diagenesis leaving a distinctive variety of chert (Magadi-type chert).

Kampfite is a rare barium silicate–carbonate–halide mineral with the chemical formula . Discovered in 1964 and described in 2001, it is named after Anthony R. Kampf. The mineral is known only from Fresno County, California.

Ganophyllite is a phyllosilicate mineral. It was named by Axel Hamberg in 1890 from the Greek words for leaf (φύλλον) and luster (γανωμα); the latter one was chosen due to the lustrous cleavages. The mineral was approved by the IMA in 1959, and it is a grandfathered mineral, meaning its name is still believed to refer to an existing species until this day. Tamaite is the calcium analogue, while eggletonite is the natrium analogue of said mineral.

Tumchaite, , is a colorless to white monoclinic phyllosilicate mineral. It is associated with calcite, dolomite, and pyrite in the late dolomite-calcite carbonatites. It can be transparent to translucent; has a vitreous luster; and has perfect cleavage on {100}. Its hardness is 4.5, between fluorite and apatite. Tumchaite is isotypic with penkvilksite. The structure of the mineral is identified by silicate sheets parallel {100}, formed by alternation of clockwise and counterclockwise growing spiral chains of corner-sharing tetrahedra. Tumchaite is named for the river Tumcha near Vuoriyarvi mas

Macaulayite is a red, earthy, monoclinic mineral, with the chemical formula (Fe3+,Al)24Si4O43(OH)2. It was discovered in the 1970s by Jeff Wilson and named after the Macaulay Institute in Aberdeen, Scotland. The only known source of macaulayite in the world is a quarry at the foot of Bennachie, Aberdeenshire, and it is formed by granite which has been weathered by tropical climates from before the last ice age. The substance is currently being studied by NASA, as it is speculated that this is the substance which gives the planet Mars its colour and it could prove that life on Mars can be susta

Cymrite is a silicate mineral with the chemical formula BaAl2Si2(O,OH)8·H2O. The mineral is named for Cymru, which is the Welsh word for Wales.

thumb|Ground Kenyaite in a sample container Kenyaite is a mineral and is a peculiar sodium silicate having a layered structure. It has a chemical formula of Na2Si22O41(OH)8 • 6H2O, which means it is made up of variations of different materials including sodium, silicon, hydrogen, and oxygen. The chemical composition of kenyaite is subject to change: when the interlayer of water has different variations; it undergoes different physical conditions; by partial to full exchange of the sodium ions by protons when kenyaite comes into contact with water. This is typical for intracrystalline reactive

Pimelite was discredited as a mineral species by the International Mineralogical Association (IMA) in 2006, in an article which suggests that "pimelite" specimens are probably willemseite (which is approved), or kerolite (which is also discredited). This was a mass discreditation, and not based on any re-examination of the type material (assuming any exists). Nevertheless, a considerable number of papers have been written, verifying that pimelite is a nickel-dominant smectite. It is always possible to redefine a mineral wrongly discredited.

Kerolite or cerolite is a metamorphic nickel bearing phyllosilicate mineral variety of talc, can be seen as a mixture of serpentine and saponite as well. It has the chemical formula . It is often considered as a talc variety and it was discredited 1979.

Zussmanite is a hydrated iron-rich silicate mineral with the chemical formula . It occurs as pale green crystals with perfect cleavage.