Pyromorphite

Pyromorphite growing at the expense of pre-existing Pb minerals (utility 01 - chloramine disinfection, phosphate corrosion control). The most abundant mineral in the surface layer had been plattnerite. Pyromorphite in distribution system corrosion scales typically starts as these small spheres. Note the plattnerite here occurs in sub-micron crystallites in thin sheets that are peeling up. This disruption may be an artefact of drying or may have been present in situ. If the latter, then these sheets could have supplied abundant particulate Pb at the tap.