Manganiferous cherts occurring in the subducted portion of the alpine belt (eclogite to blueschist facies metamorphism) present four types of structural settings: a) in stratigraphic coherency with the paleooceanic crust (ophiolites); b) in volcano-sedimentary sequences derived from disrupted ophiolite + chert + sediment associations; c) in reworked volcano-sedimentary sequences deposited on shelf or near the continent; d) in insufficiently studied terranes. In the literature, more than 100 occurrences are mentioned, but standard petrographic data are available for only about 40. Modern geochemical, mineralogical, or penological data are limited to the 6 following occurrences: Haute Maurienne in France; Alagna, St. Marcel and the upper Valtournanche in Italy; Zermatt in Switzerland; and Andros in Greece. Modification of the bulk composition occurred during metamorphism, by homogenization of the chert sequence (radiolarites and their shale partings), as well as by addition of elements through a circulation of the fluid phase as far down as the underlying ophiolites. The mineralogy includes about 100 identified species; of these, 28 groups are reviewed, with special attention to their crystal chemistry and the compositional differences derived from bulk chemical control, oxidation conditions, and changing P, T, f(O 2 ) of the polyphasal alpine metamorphism. It is noteworthy that glaucophane never occurs in cherts, although it is present in the nearby mafites. The analysis of phase compatibility points to three different assemblages: a) “oxidized,” where silicate minerals contain Mn 3+ in addition to Fe 3+ : manganic varieties of sodic clinopyroxenes and micas, piemontite, ardennite, braunite; b) “neutral,” where silicates contain Mn 2+ next to Fe 3+ , but the oxides can contain Mn 3+ : spessartine, rhodonite, pyroxmangite, pyrophanite, andradite, riebeckite, acmite but also hausmannite; c) “reduced,” where Mn is entirely divalent, and Fe 2+ is present as well as Fe 3+ . Reducing assemblages are typical of carbonate-bearing partings, where kutnahorite and rhodochrosite coexist with tephroite, rhodonite, Mn-humites; and of rare “aluminous” partings, containing jacobsite and galaxite. Numerous veins, containing minerals of any type, testify to the continuous fracture flow percolating through the metamorphosed chert sequence. Published estimates on the equilibration conditions of blueschist-facies alpine cherts vary widely: P = 5 to 14 kbar; T = 300 to 525°C; f(O2) = 10 -5 to 10 -25 bar. Such a scatter is due to the yet insufficient experimental knowledge on the Mn-Si-Al-OOH system, including the nearly complete lack of determinations of the influence of other elements (e.g. Fe, Ca, As) on the reaction topology, and the still limited study of the natural phase relations in certain critical outcrops.