When I first encountered this material as part of a huge lot of miscellaneous specimens, I almost discarded it as (at first glance) it looks like a vial of ordinary sand. However, under magnification it is revealed to be rich in small but bright and well-formed silver crystals as well as numerous fragments of glassy, tabular cerussite crystals. Unsure if this is natural material or an anthropomorphic mix...but regardless still a treat under magnification - hand lens, microscope or camera lens.