Iron ore is a commodity much of the world desperately wants.
The dull grey or red ore isn't much to look at, but heat it up, add a little carbon and you create steel - vital to the construction industry.
Unfortunately for four Rio Tinto Ltd executives arrested in China on July 5, the stakes have become very high in a bid to acquire the mineral.
Some now see the arrest of the Rio Tinto workers, including Australian man Stern Hu, as part of a broad push by China to take on the decades-old pricing system for iron ore and revamp its steel sector.
Australian attention has focused on the Rio workers, but at least seven other steel industry executives in China have been detained, with information about their plight scant.
The government-led China Metallurgical Industry Planning and Research Institute (CMIPRI), which helps plan the nation's steel industry development, has called for big changes to the sector.
Mining companies are listening.
CMIPRI vice president Li Xinchuang recently said the number of firms in the nation allowed to buy iron ore from overseas should be cut from 112 to between five and 10, potentially crippling competition.
The country's industry peak body, the China Iron and Steel Association (CISA) has called for the iron ore spot trading to be stopped.
As the world's largest exporter of seaborne iron ore shipments, Australia has a huge stake in the outcome of any changes.
In 2005 China overtook Japan to become the largest importer of Australian iron ore, and has since taken a stranglehold over the market.
Preliminary figures show that in the first part of 2009 China bought about 80 per cent of Australia's iron ore exports
Iron ore prices to large customers are set using an odd system.
A deal is done between a big iron ore producer and a major steel mill, then publicised and used as a benchmark for other mills to accept.
If steel makers don't like the price, they can try to purchase the commodity on the spot market.
But the spot market is notoriously volatile, making it tough for steel makers to plan budgets and guarantee supplies, and in recent times the spot price has been above the benchmark price.
For practical purposes once a benchmark price is set with a big mill, it is the price all major steel makers accept.
To ensure they got the deal they wanted this year, Chinese steel makers demanded that as the largest iron ore market they ought to take the lead in price negotiations.
The Chinese mills combined their forces behind the government-controlled CISA to do the negotiating for them.
From the miners' side, Australia's Rio Tinto - the world's second-largest iron ore producer - stepped up to lead negotiations.
The talks were never going to be easy.
"They (Chinese negotiators) think they can still intimidate, in the way that they do as a totalitarian government," said long-time mining analyst Gavin Wendt from Fat Prophets.
"They think they can affect the workings of a free market by simply saying they don't like something and trying to throw their weight around.
"I am sure this detention (of Stern Hu) is linked to that," he said.
Chinese official media allege Mr Hu and his Rio Tinto team bribed steel mills to find out CISA's bottom line during the talks.
The state-run China Daily newspaper claimed all 16 major steel mills in China were bribed by Rio Tinto, allegations the company says are "wholly without foundation".
All parties in the delicate iron ore negotiations were expecting a cut to prices, after the value of commodities were slashed from highs a year earlier following the global economic downturn.
CISA publicly called for a cut of between 40 and 45 per cent and was not budging, at least publicly, from that position.
One can only imagine the CISA negotiators' anger and loss of face when Rio publicly announced it had struck a benchmark deal with steel mills from China's arch-enemy Japan.
The Japanese had agreed to a 33 per cent price cut, paying far more for the ore than CISA was offering and undermining the argument that steel mills couldn't make a profit at that cost.
South Korean and Taiwanese mills quickly followed suit in accepting the price, while the world's largest steel maker, ArcelorMittal, paid slightly more for better quality iron ore from Brazil.
With CISA refusing to agree to the same terms, Chinese mills who had not clinched a deal were left hanging, and forced to pay spot prices, or an index price based on market indices.
It is impossible to know exactly what prompted China's secret police to seize Mr Hu and his workmates.
Some have linked it with Chinese reaction to Australia's defence White Paper, seen as hostile towards China, the issue of Tibetan independence, or a failed bid by a big Chinese state-owned company, Chinalco, to buy a chunk of Rio Tinto.
China's media though have associated it iron ore prices, and stealing "state secrets".
On websites Chinese netizens have been quick to claim Australia's reaction to the Rio Tinto case smacks of racism, invoking memories of Pauline Hanson.
Economist and former Australian Ambassador to China, Professor Ross Garnaut, recently told ABC radio that issues surrounding iron ore pricing this year will forever change the benchmark system.
Already changes are becoming evident.
BHP Billiton has said that only 23 per cent of its total iron ore volumes for 2009 have been sold at the benchmark rate, a landmark change for the company.
While 47 per cent of volumes are yet to be settled, about 30 per cent have been signed at quarterly negotiated, index-based or spot prices.
In July Rio Tinto revealed half its iron ore deliveries had been sold on the spot market, showing it too was willing to use a more fluid pricing system.
As spot prices have been strong, the affect of the spot trading has been to boost the companies' bottom lines, but this may not always be the case.
Privately Australian mining companies have mixed messages about what the arrest of Mr Hu and his colleagues means.
"I don't think they (Chinese companies) have done themselves any favours," Mr Wendt told AAP.
"It will certainly cause business groups, companies and investors to think twice when dealing with China," he said.
