Zincolivenite, Ferrilotharmeyerite

This striking specimen features numerous intense, electric-green crystals of zincolivenite, richly aggregated on little to no matrix. Nestled in the nooks and crannies are fibrous, red-brown tufts of cadmium-rich ferrilotharmeyerite, a rare calcium–iron–zinc arsenate first described from Tsumeb (type locality) and seldom encountered anywhere else in such attractive, crystallized form. Some light olive-green prisms of olivenite can be observed under the microscope, providing an elegant association of related species.

Historically, crystals of zincolivenite from Tsumeb were long misidentified and labelled as "adamite" or, more commonly, as "cuproadamite" on older labels. Only in recent decades have detailed analyses confirmed them as zincolivenite, a relatively new species formally recognized after its approval by the IMA. According to mindat.org, zincolivenite is an intermediate member of the solid-solution series between olivenite and adamite, with an ideal Zn:Cu ratio of 1:1, not to be confused with zinc-bearing olivenite.

Together, the combination of zincolivenite, ferrilotharmeyerite, and olivenite beautifully reflects the extraordinary paragenesis of the Tsumeb deposit, one of the most celebrated mineral localities in the world. Scientifically important, mineralogically significant, and aesthetically appealing, this piece highlights the unparalleled diversity and uniqueness of the Tsumeb orebody.