Platinic Chloride (H2PtCl6)
Furanyl fentanyl forms clusters of thin, colorless plates with platinic chloride reagent. The crystal habit differs between the three solvents of water, 10% hydrochloric acid and 10% acetic acid. The largest and most reliable crystals are formed with 10% hydrochloric acid. In water, the individual crystals in the cluster are a mix of narrow rod like structures and light feathery plates. The clusters in 10% hydrochloric acid are larger with a mix of short and long plates. The clusters get tighter with short and broad plates in 10% acetic acid. All three forms of the crystals appear bright under crossed polars.
Platinic Bromide (H5PtBr6)
Platinic bromide gives characteristic sheaves of short red rods with furanyl fentanyl. The rods appear a bright yellow under crossed polars and form quickly and reliably.