Fig. 6From: The formation of spinel-group minerals in contaminated soils: the sequestration of metal(loid)s by unexpected incidental nanoparticlesTEM images of features composed of Ni-bearing spinel-group minerals: a, b magnetite cubes; c spherical magnetite NP on jarosite surface; d row of magnetosomes; e parallel-growth of maghemite needles; f surface features on an individual maghemite needle; the presence of attached nanoparticles on the surfaces of the magnetite cube and maghemite needle are indicated with arrows in b and f; minerals are labelled with the same numbers as in Fig. 5Back to article page