An Etymological Dictionary of the German Language/Mantel
Mantel, m., ‘cloak, mantle,’ from the equiv. MidHG. mantel, mandel, OHG. mantal, mandal, m.; on account of the non-permutation of t to z the word cannot be cognate with MidE. mantel, E. mantle, OIc. mǫttul, m., ‘cloak,’ and hence it is not derived from the same root as Gr. μανδύας, ‘upper garment.’ The Teut. cognates are more probably based on Lat. mantellum, from which Ital. mantello and Fr. manteau are derived.