"Store Didoni" Collection, Macherio (MB)

Typically originating from the Democratic Republic of the Congo (Katanga) and Zambia, it is a form of malachite consisting of very fine acicular fibers intertwined irregularly, giving the rough surface a velvety, opaque, and “felted” appearance, similar to a deep green, mossy carpet. It forms in the oxidation zone of copper deposits through rapid precipitation from supergene solutions rich in copper and carbonates, without enough time to develop the concentric bands typical of the botroidal variety. Hardness 3.5–4 on the Mohs scale, density 3.6–4.0 g/cm³; polishing reveals a more uniform and deeper grain than in other forms.

Sought after by collectors for its raw, velvety, and striking appearance, it is often displayed in unpolished blocks to highlight its natural texture; it is also the preferred form for crafting spheres and stone objects with uniform color; it must be handled with caution due to the toxicity of copper dust during processing.