This is a beautiful multi-colored piece from the historic Cerro Gordo Ag-Pb-Cu-Zn Mine in California that produced a modest amount of secondary minerals, including Linarite and Caledonite as in this specimen! Abundant, <1 to 3mm, royal blue, prismatic, scintillating Linarite crystals decorate the inside of the elongated vug on this piece along with numerous tufts of glistening, bluish green Caledonite for a super colorful combination. Rich and significant for a California specimen, both species also line fracture surfaces on and in the piece for more coverage! One fracture surface on the far left end of the piece has some pale green crystals that look like Smithsonite. It's a good piece for the Linarite and great for the Caledonite, especially for California! Ex Bob Reynolds collection, and in all likelihood self collected by him as he visited the site many times.