Reuters reports 50,000 protesters battled police in Chile's capital on Thursday, the second day of a two-day strike against unpopular President Sebastian Pinera. A recent poll put the right-wing leader's approval rating at only 26%, below even that of dictator General Pinochet, who ruled the country for 17 years from 1973. The protests follows recent strikes in the copper sector over pay and a campaign against a massive coal mine on an island in Patagonia amid accusations that billionaire Pinera’s shareholding in the developer, Copec, constitutes a serious conflict of interest.

FT reports iron ore prices hit a three-month high above $180 a tonne on Thursday as supply outages and strong demand from China underpinned the steelmaking commodity. Started in 2008, derivatives trading in iron ore is up fourfold this year after setting a record in July, but he world’s top three miners – BHP Billiton, Vale and Rio Tinto – control nearly 70% of the 1 billion tonne annual seaborne trade and dominate price talks. BHP this week announced record profits on back of earnings from iron ore, its biggest division, which jumped 122% to $13.3 billion and CEO Marius Kloppers said unlike the situation in coal, global iron ore supplies are being 'overestimated'.

Reuters Africa reports that copper rose 2 percent at a three-week high.

SRK Consulting has opened a practice in Ghana’s capital, Accra. This follows several decades of involvement in West Africa and will consolidate SRK’s position in the region.

Caterpillar Inc. on Aug. 24 announced an expansion of the company’s operations in China in what the company says is in support of the company’s strategy to grow its business to a leadership position in China.

Interfax reports Russia state-owned diamond miner Alrosa is up 22% on the country's trading board for unlisted stocks since it was first quoted there on July 18. The price of US$31,495 per share, implies a market value of $8.6 billion. Alrosa accounts for around 25% of world output and for the full year sales of $4.7 billion is expected. The secretive firm has been feeding the market more information recently in anticipation of a 2012 public offering that seeks to raise up to $3 billion.

Every day up to 400 trucks leave the coal stockpile Kohlenhuck of Deutsche Steinkohle in Kamp-Lintfort, Germany. A special FRUTIGER De-Mucking System washes the trucks before they enter the public road.

24/7 Wall St says the global diamond mining industry may be one of the world’s best-kept secrets and diamond mining is not unlike the oil business, where about 100 massive fields supply about half the world’s oil.

Gold for December delivery fell more than $50 to $1,710 an ounce in afternoon trade in London on Thursday, bring its losses since the record high of Monday to 10%, the worst slump since March 2008. On Wednesday, the Chicago stock exchange operator CME followed a move by the Shanghai Gold Exchange by increasing the margin requirement as a way to “ensure adequate collateral coverage.” The minimum cash deposit to borrow from brokers to trade gold futures will rise 27% to $9,450 per 100-ounce contract at the end of today. Silver slumped as much as 35% in London in about three weeks from its April 25 record of $49.79 an ounce after CME announced margin increases.