This document is part of Subvolume I5a ‘Phyllosilicates' of Volume 27 ‘Magnetic properties of non-metallic inorganic compounds based on transition elements' of Landolt-Börnstein - Group III ‘Condensed Matter'. It presents true micas with regard to their nomenclature, crystal structures, lattice parameters, neutron diffraction data, magnetic properties, nuclear gamma resonance (NGR) data, nuclear magnetic resonance (NMR) data, heat capacities, electrical resistivities, X-ray absorption spectroscopy data and optical properties. Mineral names contained in this document: aluminoceladonite, amphibole, anandite, annite, annite/ferri-annite, annite-fluorannite, annite-phlogopite, annite-siderophyllite, aspidolite, astrophyllite, augite, biotite, bityite, boromuscovite, brammallite, celadonite, chernykhite, chromoceladonite, chromphyllite, clintonite, eastonite, ephesite, ferri-annite, ferriphlogopite, ferro-aluminoceladonite, ferroan phlogopite, ferroceladonite, fluorannite, fluoromica, fluorophlogopite, fluoropolylithionite, glauconite, glauconite , glauconite, hendricksite, illite, illite/smectite, illite-paragonite, kaolinite, kinoshitalite, kinoshitalite-ferrokinoshitalite, lepidolite, magnesio-margarite, manganophyllite, margarite, masutomilite, mica, montdorite, montmorillonite, mullite, muscovite, muscovite-aluminoceladonite, muscovite-celadonite, muscovite-paragonite, nafertisite, nanpingite, nontronite, norrishite, oxyannite, oxybiotite, oxy-ferri-annite, paragonite, paragonite-muscovite, phengite, phlogopite, phlogopite-annite, phlogopite-eastonite, phlogopite-preiswerkite, phyllosilicate, polylithionite, polylithionite-siderophyllite, polylithionite-trilithionite-muscovite, preiswerkite, protolithionite, pyrophyllite, Rb-tetra-ferri-annite, Rb-TFA, roscoelite, saponite, sericite, siderophyllite, siderophyllite-eastonite, siderophyllite-polylithionite, sillimanite, smectite, taeniolite, tainiolite, talc, talc-pyrophillite, tetra-ferri-annite, tetra-ferri-phlogopite, tobelite, trilithionite, trilithionite-annite-, trilithionite-polylithionite, vermiculite, wonesite, zinnwaldite. Substances contained in this document (element systems and chemical formulae): A-Al-H-Mg-O-Si: A(Mg3-xAlx)(Si3-xAl1+x)O10(OH)2 (A = K, Na). A-Al-M-N-O-Si: AM2-3☐1-0T4O10N2 (A = K+, Na+, Cs+, NH4+, Rb+, Ca2+, Ba2+; N = F-, OH-, Cl-, O2-, S2-; T = Si, Al; M = Mg2+, Fe2+, Fe3+, Li+, Al3+, Tin+, Cr2+, V, Zn). Al-B-Ca-F-H-K-Li-Mg-O-Rb-Si: (K0.89Rb0.02Ca0.01)(Al1.93Li0.01Mg0.01)(Si3.06B0.77Al0.17)O9.82(OH)2.02F0.16, (K0.89Rb0.02Ca0.01)(Al1.93Li0.01Mg0.01)(Si3.06B0.77Al0.17)O9.82[(OH)2.02F0.16]. Al-B-Fe-H-K-Mg-Mn-Na-O-Si-Ti: (K0.93Na0.052B0.007)(Ti0.023Mn0.020Fe3+0.149Mg0.099Al1.718)(Si3.055Al0.945)O10(OH)2. Al-B-H-K-O-Si: KAl2☐BSi3O10(OH)2. Al-Ba-Ca-F-Fe-H-K-Mg-Na-O-Si-Ti: (K0.90Na0.06Ca0.01Ba0.01)(Al1.83Fe2+0.04Fe3+0.04Mg0.09Ti0.01)(Si3.11Al0.89)O10(OH)1.98F0.03. Al-Ba-Ca-Fe-H-K-Mg-Mn-Na-O-Si-Ti: (Na0.88K0.10Ca0.01Ba0.01)(Al1.97Ti0.007Fe0.01Mn0.002Mg0.006)(Si3.01Al0.99)O10(OH)2,… [ABSTRACT FROM AUTHOR]