Fibrous Malachite - Mashamba West Mine, Sicomines copper-cobalt project, Mutshatsha, Lualaba, DR Congo

Cu₂(CO₃)(OH)₂

Fibrous Malachite from Mashamba West Mine

The Mashamba West Mine, located in the Sicomines copper-cobalt project in the Mutshatsha territory of Lualaba Province, Democratic Republic of Congo (DRC), is renowned for its remarkable mineral specimens, particularly fibrous malachite. The region is globally recognized for its rich deposits of copper and cobalt, which have made it a hotspot for mining and mineral collecting.

Key Characteristics of Fibrous Malachite:

1. Appearance:
   • Vibrant green color with silky luster.
   • Characteristically fibrous texture, often radiating in aggregates.
   • Forms botryoidal (grape-like) surfaces or velvety coatings.
2. Composition:
   • A hydrated copper carbonate mineral: $C{u}_2(C{O}_3)(OH{)}_2$.
3. Crystal System:
   • Monoclinic.
4. Formation:
   • Typically forms as a secondary mineral in oxidized zones of copper deposits.
   • Results from the alteration of primary copper minerals such as chalcopyrite or native copper.

Mashamba West Mine and the Sicomines Project:

• Location: The mine is situated within the prolific Katanga Copperbelt, one of the richest sources of copper and cobalt in the world.
• Geological Context:
  • The region hosts deposits in sedimentary rocks, particularly in the "Roan Group," a sequence of sedimentary formations known for their high-grade copper-cobalt ores.
  • The oxidized zones of these deposits are where fibrous malachite typically occurs.
• Sicomines Project:
  • A major mining operation jointly operated by Congolese and Chinese entities, focusing on both copper and cobalt extraction.
  • The project has contributed significantly to the DRC’s economy while producing collectible mineral specimens.

Significance of Fibrous Malachite from Mashamba West:

1. Collector's Value:
   • Specimens from this locality are highly sought after for their intense color, unique fibrous structure, and aesthetic appeal.
   • Pieces often feature a velvety surface with vibrant hues, making them standout items in mineral collections.
2. Scientific Interest:
   • Malachite serves as an indicator mineral, providing insights into the oxidation and weathering processes in copper deposits.
   • Its formation reflects the geochemical interactions in the supergene zone (near-surface environment) of copper ore bodies.
3. Economic and Cultural Importance:
   • While prized as a gemstone and ornamental material, malachite also symbolizes the wealth of natural resources in the Katanga Copperbelt.

Associated Minerals:

In the Mashamba West Mine, fibrous malachite often occurs with:

• Azurite: Another copper carbonate mineral, deep blue in color.
• Cobaltite: A cobalt sulfide mineral, reflecting the cobalt-rich nature of the deposit.
• Cuprite: A red oxide mineral of copper.
• Heterogenite: A common cobalt oxide in the DRC.
• Chrysocolla: A secondary copper silicate mineral with a bright blue-green hue.

Summary

Fibrous malachite from Mashamba West Mine is not only a geological marvel but also a testament to the mineralogical richness of the DRC. Its striking aesthetics and mineralogical associations make it a gem in the world of mineral collecting and research.

Approx. specimen size: 90mm x 60mm x 40mm