Chrysocolla pseudomorphs after Azurite - Lupoto Mine, Kakumba, Haut-Katanga, DR Congo

A striking chrysocolla pseudomorph after azurite from the Lupoto Mine, Kakumba, Haut-Katanga, Democratic Republic of the Congo. The specimen displays an exceptionally vivid turquoise-blue to blue-green colour across an intricate, highly textured and sculptural surface.
These unusual specimens are believed to have formed through a complex, multi-stage alteration process. The original crystals were azurite, which was subsequently altered to malachite while retaining the external crystal form. Later silica-rich fluids transformed much of the malachite to chrysocolla, again preserving the shape of the earlier crystals. In some areas, incomplete replacement left malachite cores surrounded by chrysocolla; subsequent removal of these cores produced hollow forms, creating features that may be described as epimorphs.
This specimen shows particularly attractive projections, layered textures and hollow crystal forms, giving it considerable three-dimensional character. Areas of dark brown matrix provide strong contrast with the intense turquoise chrysocolla, while the upright form makes it an especially effective display specimen. There are a few minor nicks present.
Material of this type was recovered from the Lupoto area during the mid-2010s from a limited find that has not been repeated. The combination of vivid colour, unusual pseudomorphic formation and distinctive sculptural habit makes this an excellent example of this unusual Congolese material.

Mineral: Chrysocolla pseudomorph after Azurite
Locality: Lupoto Mine, Kakumba, Haut-Katanga, Democratic Republic of the Congo
Crystal System: Monoclinic (original Azurite crystal form)
Mineral Class: Silicates
Provenance: Ex Mike Clark Collection
Dimensions: 5 × 3 × 3 cm