By the construction of the Nimy-Blaton Channel, an interesting geological profile of 25 m thickness was exposed over a length of nearly 1000 m. This whole zone contained a spectacular phosphate paragenesis. The first mineral he described was crandallite, and lateron a whole list of other minerals followed. Many years later, in 1983, Peacor et al. described the new mineral and not only confirmed the absence of Mn, but also proved that all the iron present was trivalent, and the X-ray diffraction pattern differed significantly from that of strunzite. It forms aggregates and crusts of light-yellow to brownish prismatic crystals, as well in random orientations as in spherical aggregates.
Many crystals are bent or deformed.
This locality is about 80 km from Blaton. Ferristrunzite crystals from Blaton, Belgium. See scale bar on the image.