<p>Quasi-static hysteresis loops of assemblies of magnetosome chains of various geometric configurations have been calculated using numerical simulation. A detailed comparison is carried out of the quasi-static hysteresis loops of assemblies of single and double magnetosome chains, as well as assemblies of flux-close rings. It was shown that the hysteresis loops of the studied assemblies differ significantly from each other and from the hysteresis loop of a random assembly of non-interacting spherical magnetite nanoparticles. Therefore, the presence of biogenic magnetite in natural samples of weakly magnetized ancient rocks and ocean sediments can, in principle, be detected from standard measurement of the quasi-static hysteresis loops of the sample under study.</p>