A very beautiful example of hexagonal pyromorphite crystals, that have pseudomorphed to light blue plumbogummite.  There are various "styles" of these specimens from different areas of the discovery all with different degrees of pseudomorphing.  This particular style is one of my favorites-- there is enough pseudomorphing present to appreciate the blue color of the plumbogummite, but the sharpness of the original pyromorphite crystals are retained.  For this type of piece, the crystals are also a bit larger than usual, and the specimen is more rich than average.