Zincolivenite

This striking thumbnail specimen features an aggregate of lustrous, crystals of Zincolivenite. The crystals exhibit an intense, electric-green colour with superb lustre, there's a crevice near the bottom with acicular tufts of an unknown yellow mineral.

Zincolivenite, a rare and relatively new species, is the intermediate member of the solid-solution series between olivenite and adamite, with an ideal Zn:Cu ratio of 1:1. This relationship explains its structural and visual similarities to both species. Historically, such crystals from Tsumeb were misidentified, often labelled as "adamite," "Zn-olivenite," or more commonly, "cuproadamite" on older labels. Only in recent decades, after careful analyses and eventual IMA approval, was zincolivenite formally recognized as its own distinct mineral species.