The first detailed crystallo-chemical and crystallographic description of cronstedtite with extraterrestrial origin has been presented in this study. The analysed crystals have been found in the Paris meteorite, which is the least altered carbonaceous chondrite currently known, and they result from the pseudomorphism of anhydrous silicates. 3D electron diffraction data have been collected by electron diffraction tomography and used to identify the cronstedtite polytypes, because of their small size. All identified polytypes are MDO (Maximum degree of order), and the most abundant one is 1T. Many other crystals also belong to the Bailey's group (or OD subfamily) C, but their stacking disorder hampers the polytype identification. Only in one crystal, the 3T and 2M1 polytypes are recognised. TEM-EDX data indicate that the chemical composition of the crystals is similar, regardless their polytypic sequence.

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