As demand for the tin ore cassiterite soars, special forces units of Brazil’s Ibama environment agency must play a cat and mouse game with the thousands of illegal miners pouring into Yanomami reserves In the back yard of the federal police headquarters in Roraima, the northernmost state of Brazil, giant sacks lie strewn and overflowing with a jet-black, gravel-like mineral: cassiterite. Although less high-profile than other items seized during a crackdown on illegal mining in this Amazon state – including a Sikorsky S-76 helicopter painted in the colours of the Brazilian flag – cassiterite has become so sought-after that it is nicknamed “black gold”. Cassiterite is the chief ore of tin, a less heralded but critical mineral for the energy transition. It is used in coatings for solar panels, lithium-ion batteries and solder for electronics, including wind turbines, mobile phones, computers and industrial alloys. Continue reading...