The Rio Tinto Ltd (ASX: RIO) share price is another struggling miner on Tuesday, down 1.55% to $108.975.
The S&P/ASX Materials (INDEXASX: XMJ) has been under heavy selling pressure as of late, down 10% in the past month.
What's driving the Rio Tinto share price on Tuesday?
Iron ore prices plunge to 10 month lows
Tumbling iron ore prices continue to send shock waves across the materials industry, with the Fortescue Metals Group Ltd (ASX: FMG), BHP Group Ltd (ASX: BHP) and Rio Tinto share prices extending losses on Tuesday.
Benchmark iron ore prices fell another US$12.33/t or 8.8% to US$132.38/t on Monday, according to Fastmarkets MB.
The share prices of iron ore miners are now rapidly winding back as iron ore prices begin to retreat.
The sudden plunge in spot prices has witnessed declines between 14% to 21% in the past month for the three iron ore giants.
Military coup sparks development concerns
Meantime, special forces in the African nation of Guinea seized power on Sunday, closing both land and air borders and arresting the president.
The political instability in the region could impact mining companies, more specifically, Rio Tinto's Simandou joint venture (45% ownership).
The Australian quotes Commonwealth Bank of Australia (ASX: CBA) mining and energy commodities analyst Vivek Dhar who said the outlook for Simandou looks cloudy after the coup.
"Funding was already challenging given the weak economic rationale to build the project. However, funding will prove even more challenging in the face of political instability," said Mr Dhar.
The project is expected to produce 150 million tonnes per annum of iron ore at full capacity.
To add some perspective, Rio Tinto shipped 154.1 million tonnes in 1H21.
Rio Tinto share price snapshot
Rio Tinto's recent underperformance has dragged its shares into negative year-to-date territory, down 4.57%.
At its highest point in the calendar year, the mining giant's share price was up as much as 16% on 4 August.
