Silicate minerals#Phyllosilicates

As phyllosilicates ( sheet silicates, phyllosilicates ) is called silicates, silicate anions which consist of layers of corner SiO4 tetrahedra. These layers or double layers are connected to each other not via more Si -O bonds to scaffolding.

At the Department of silicates include major groups of rock-forming minerals such as mica group, chlorite, kaolin and serpentine. The technically important and common clay minerals in sedimentary rocks are also phyllosilicates.

The layered structure of these minerals in determining the shape and properties of the crystals. They are usually platy to flaky with good to perfect cleavage parallel to the layers. The multiplicity of rings, from which make up the silicate layers, often determines the symmetry and shape of the crystals. Apophyllite ( layers of four- membered rings ) is tetragonal and forms four-sided tabular to prismatic crystals. The minerals of the mica group form (silicate layers of six-membered rings ) tabular to bladed crystals with pseudohexagonal symmetry. The good translation capability along the layers due to the strong deformation of the layer silicates. H2O molecules and large cations can be incorporated between the layers. Phyllosilicates are often capable of swelling and with their cation exchange capacity important for soil fertility.

Phlogopite

Apophyllite

Talc

Carletonit

Classification

Silicate classification according to Liebau

Liebau considered the phyllosilicates as a nexus of silicate chains into layers, which are unlimited in two dimensions and split the layer silicates based on the periodicity and branching of the silicate chains which make up the layers as well as the multiplicity of the silicate layers.

Periodicity:

It indicates how many chain links silicate (SiO4 - tetrahedron ) repeats the structure of a chain. The periodicity of natural sheet silicates is usually small and is 2 ( mica group ), 3 ( eg Dalyit ), 4 (eg Apophyllite ) or 6 (eg Pyrosmalit ).

Raw branches of two single layer in sepiolite

Raw branches of three single layer in Dalyit

Raw branches of four single layer in Apophyllite

Raw branches sixes single layer in Pyrosmalit

Branching:

It indicates whether a silicate chain branching from other SiO 4 tetrahedra. A distinction is made between open branched layer silicates ( eg Zeophyllit ) and cyclic branched layer silicates ( eg Delhayelit ), in which the branching of the chain SiO4 tetrahedra form closed rings.

Open branched foursome single layer of Zeophyllit

Multiplicity:

It specifies how many silicate layers are linked to one another to form multiple layers. So far, no phyllosilicates with a multiplicity > 2 are known.

Cyclic branched three double layer of Delhayelit

Cyclic branched sixes double layer of Carletonit

Strunz

Unlike the ring silicates and chain silicates Strunz'sche the classification of phyllosilicates does not assume the nomenclature and criteria of Libau. The Strunz'sche systematics considers the silicate rings, from which make up the layers and divided the Department of phyllosilicates ( 9.E ) according to the multiplicity of these rings, the multiplicity of layers as well as the connection between the layers of the octahedral cations.

Simple 9.EA tetrahedral layers with 4 -, 5 - (6 - ), and 8 -fold rings:

9.EA.05 gillespite Group
9.EA.10 Ekanit Group
9.EA.15 Apophyllitgruppe
9.EA.20 magadiite Group
9.EA.25 Dalyit Group
9.EA.30 Sazhinit Group
9.EA.35 Armstrongit Group
9.EA.40 Okenit Group
9.EA.45 Nekoit Group
9.EA.50 Cavansit Group
9.EA.55 Pentagonit Group
9.EA.60 penkvilksite Group
9.EA.65 Nabesit Group
9.EA.70 Ajoit Group
9.EA.75 Zeravshanit Group
9.EA.80 Bussyite - (Ce)
9.EA.85 Plumbophyllit Group

9.EB bilayers with 4 - and 6 -fold rings

9.EB.05 Rhodesit Group
9.EB.10 Delhayelith Group
9.EB.15 Monteregianit Group
9.EB.20 Carletonit Group

9.EC layer silicates with mica panels (three- layer silicates), composed of tetrahedral and octahedral

9.EC.05 Talk Group
9.EC.10 pyrophyllite group
9.EC.15 muscovite group
9.EC.20 phlogopite group
9.EC.25 illite group
9.EC.30 Margarit Group
9.EC.35 clintonite Group
9.EC.40 montmorillonite group
9.EC.45 saponite group
9.EC.50 vermiculite group
9.EC.55 chlorite group
9.EC.60 corrensite Group
9.EC.65 Macaulayit Group
9.EC.70 Burckhardtit Group
9.EC.75 Surit Group
9.EC.80 Kegelit Group

9.ED phyllosilicates with kaolinite layers (two- layer silicates), composed of tetrahedral and octahedral

9.ED.05 kaolinite group
9.ED.10 halloysite group
9.ED.15 serpentine group
9.ED.20 Bismutoferrit Group

9.EE Simple tetrahedral nets of six-fold rings, connected by octahedral nets or straps

9.EE.05 Bementite Group
9.EE.10
9.EE.15 Schallerit Group
9.EE.20 palygorskite group
9.EE.25 sepiolite group
9.EE.30 Gyrolith Group
9.EE.35 Reyerit Group
9.EE.40 natrosilite Group
9.EE.45 makatite Group
9.EE.50 Varennesit Group
9.EE.55 Rait Group
9.EE.60 Intersilit Group
9.EE.65 Shafranovskit Group
9.EE.70 Zeophyllit Group
9.EE.75 Minehillite
9.EE.80
9.EE.85 Lalondeite

9.EF simple networks of six-fold rings, connected by M, M, etc.

9.EF.05 Petalitos Group
9.EF.10 sanbornite Group
9.EF.15 Searlesit Group
9.EF.20 Silinait Group
9.EF.25 kanemite Group
9.EF.30 Yakovenchukite - (Y)

9.EG double networks with six times and larger rings

9.EG.05 known Cymrite Group
9.EG.10 Naujakasit Group
9.EG.15 Dmisteinbergit Group
9.EG.20 Kampfit Group
9.EG.25 stratlingite Group
9.EG.30 Ganophyllit Group
9.EG.35 Zussmanit Group
9.EG.40 stilpnomelane group
9.EG.45 Latiumit Group
9.EG.50 Jagoit Group
9.EG.55 Wickenburgit Group
9.EG.60 HyttsjöIt Group
9.EG.65 Armbrusterite Group
9.EG.70 Britvinite
9.EG.75 Bannisterite

9.EH transition structures between phyllosilicates and other silicates

9.EH.05 Neptunite Group
9.EH.10 grumantite Group
9.EH.20 ussingite Group
9.EH.25 Leifit Group
9.EH.30 Nafertisit Group

9.EJ Unclassified phyllosilicates

9.EJ.05 Lourenswalsit
9.EJ.10 Middendorfit Group

Prehnite Okenite Cavansite Ajoite

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