Investors have been selling the miner's shares today after broad market weakness offset some positive news.
In respect to the former, at the time of writing the ASX 200 index is down 0.5% following a poor night of trade on Wall Street.
As for the latter, this morning Rio Tinto announced the approval of a US$77 million (A$110 million) pre-feasibility study (PFS) to progress development of the Rhodes Ridge project in the East Pilbara in Western Australia.
Management notes that the project is one of the world's best undeveloped iron ore deposits. It contains 6.8 billion tonnes of mineral resources at an average grade of 61.6% Fe, including 5.3 billion tonnes at 62.2% Fe and 0.6 billion tonnes at 63.9% Fe.