3,4-MDPV forms two crystal forms with the platinic bromide reagent. Both crystal forms are observed simultaneously and are shown in the first image. Thin, flat, squarish plates with angular ends are suspended in the drop. They may appear as needles or blades when oriented on their sides. They are bright under crossed polars and appear as orange, yellow or green plates. The second form of crystal are small, thick rectangular twinned tablets that are formed on the surface of the glass slide. They appear a deep orange under crossed polars. Both forms of crystals cannot be easily isolated from the reagent for IR microspectroscopy.