Tarbuttite is a very rare zinc phosphate and the Kabwe (Broken Hill) Mine of Zambia is the Type Locality. This plate is composed purely of intergrown Tarbuttite crystals that are glassy, with one side of this piece having an iron oxide tint and the reverse side being completely glassy and gemmy, with clusters of smaller intergrown crystals. Interestingly, the tinted side has the largest and best-defined crystals, with some reaching over 1 cm. There is some small bruising on both sides, the natural result of having a hardness of 3 1/2. This fine miniature was in the collection of the British Museum. Rich, burnt-orange fluorescence. Probably from the mid-1900s