Phosphohedyphane (rare) coating Cerussite

Item Description

A notably hard to find specimen from a recent discovery at the Mfouati Mine in Republic of the Congo featuring soft green to beige colored Phosphohedyphane (a rare member of the Apatite Group) which partially coated smoky, translucent crystals of Cerussite measuring up to about 1.5 cm, on oxidized matrix. According to a the paper by Manecki, Kwas´niak-Kominek, Majka and Rakovan, the Phosphohedyphane forms as a result of the Cerussite being exposed to a phosphate solution and, "proceeds in stages via an interface-coupled dissolution–precipitation mechanism through which PbCO3 is replaced by lead phosphates". So the Phosphohedyphane literally forms directly out of the Cerussite, by directly taking lead away from the crystals. In the case of this specimen, the Cerussite still remains, but you can see a slight amount of etching on the surface where it has been partially dissolved. Very few of these exist, only two pockets were found according to our source, so if you collect secondary lead minerals, unusual pseudomorphs/replacements or you just like minerals from Republic of the Congo, don't miss out on this one.