FIBF forms variations of clusters of colorless crystals with platinic chloride. The clusters are tight with short, thin needles in aqueous solutions. The clusters get looser and larger with 10% acetic acid. The individual crystals in the clusters formed are light and feathery blades. The crystals with 10% hydrochloric acid are tight clusters with very short needles that appear as dark dots under 100x magnification.

The larger clusters allow for a study of the crystals by IR microspectroscopy.