What happened to Argyle Diamond Mine in November 2020?

• A. Continued operations at reduced rate
• B. Ceased all production and mining operations
• C. Began producing synthetic diamonds
• D. Changed ownership with a new partner

Answer: (B)

The question tests understanding of a major mine lifecycle event: closure. Argyle Diamond Mine in Western Australia stopped all production and mining operations in November 2020. After decades of activity, Rio Tinto announced that Argyle would cease mining due to depleted ore grades and ongoing cost pressures, and the operation moved into care and maintenance as it transitioned toward closure and rehabilitation. This is why the correct choice is that mining and production were ceased. The other options don’t fit: there wasn’t a shift to reduced-rate production, no move to synthetic diamond production, and there wasn’t a change in ownership at that time.