Huanuni mine

The Huanuni mine sits in the Pantaleón Dalence Province of Oruro Department, Bolivia, roughly 60 km south of Oruro city. Oruro is centrally located in Bolivia, about halfway between La Paz and Sucre, at an elevation of around 3,700 meters in the Andean Altiplano. This high plateau region is known for its rugged terrain and is part of Bolivia's tin mining heartland. Nearby, other notable mining localities and the culturally rich city of Oruro, famous for its carnival, add to the area's significance.

The Huanuni mine is renowned for its cassiterite deposits, making it the world's richest source of this tin ore, with secondary enrichment forming thick veins of cassiterite breccia. It also hosts 89 valid minerals, including rare finds like aheylite and nikischerite, both type localities, making it a treasure trove for mineral enthusiasts seeking unique specimens.

The mine's host rocks are primarily sedimentary graywacke and metamorphic schist, with the ore occurring in brecciated veins. These veins result from secondary enrichment processes, involving oxidation and leaching of sulfides, typical of Andean mineral deposits linked to fault zones and hydrothermal activity.

Discovered in the 19th century, the Huanuni mine was initially mined with simple tools and donkeys for transport. It reached its peak from the 1930s to the late 1940s as the world's largest underground tin mine. Originally owned by Don Vicko Orlandini, it was later sold to tin baron Simón Iturri Patiño. Nationalized and now operated by Comibol, it remains Bolivia's largest underground tin mine, with ongoing efforts to expand despite past conflicts, such as the 2006 clashes between cooperative and state miners.

Oruro is famous for Carnaval de Oruro, a UNESCO-recognized festival blending indigenous and Christian traditions, featuring colorful parades and dances like the diablada. Local specialties include charquekan, a dish made from dried, salted meat (charque), often served with corn and potatoes, reflecting the region's mining and highland culture. Notable figures include Evo Morales, born in Oruro Department, adding to the area's historical significance.

Oruro's climate is cold and temperate, classified as Cwb by Köppen, with average temperatures around 9°C and annual rainfall of 669 mm, mostly in summer. The high-altitude Andean ecology supports unique flora and fauna, but mining activities, particularly waste from Huanuni, have raised environmental concerns, impacting downstream communities and leading to its declaration as an Environmental Emergency Zone in 2009.