Stocks to watch on Tuesday STOCKS to watch on the Australian stock exchange on Tuesday, July 30: OZL - OZ MINERALS - down eight cents, or 1.94 per cent, at $4.05 OZ Minerals will take a hit of up to $240 million, largely due to lower copper and gold prices. RIO - RIO TINTO - down 13 cents, or 0.23 per cent, at $57.11 Rio Tinto has agreed to sell its majority stake in a New South Wales copper and gold mine to a Chinese firm. Underground development at the company's Oyu Tolgoi copper mine in Mongolia has also been delayed while the company waits for financing approval from the country's government. Gold miner Ramelius Resources will post a pre-tax loss of about $70 million for the 2012/13 financial year due to writedowns on the value of its assets. WHC - WHITEHAVEN COAL - down three cents, or 1.41 per cent, at $2.10 Falling coal prices have dampened the effect of a strong increase in production for Whitehaven Coal. WOW - up 16 cents at $33.77 Woolworths releases its sales results for the fourth quarter of the 2012/13 financial year on Tuesday.