English: Magnetite magnetosomes with elongated octahedral habits in the magnetotactic Gammaproteobacteria strain SS-5. (A) TEM image of a chain of highly elongated magnetosomes. Black arrows mark crystals with pronounces octahedral facets, and white arrows point to magnetosomes with a “waisted” appearance, probably a result of twinning. (B) TEM image of part of a magnetosome chain with elongated octahedral habits (marked by black arrows and modeled in the lower left), a twinned crystal (marked by a white arrow), and a magnetosome showing slightly irregular surfaces, elongated approximately parallel to [111] (as indicated in the image). (C) High-resolution TEM image of the magnetosome in the lower right in (B), viewed along [1–10], as indicated by the Fourier transform in the lower right. The surfaces of the crystal slightly deviate from the octahedral planes as marked in the image.