Wild price swings in the iron ore and coal markets have ultimately failed to dampen investor appetite for Australia's largest mining stocks, despite Australia's largest export officially sliding into bear market territory. 

Lower steel demand in China saw the iron ore price plummet 6.8 per cent on Friday, capping off three weeks of sustained losses which have erased all of this year's gains. 

Ore with 62 per cent content in Qingdao has fallen more than 20 per cent since its February 21 peak and is now officially classified as in a bear market.

But investors in Australia's resource giants, BHP Billiton and Rio Tinto, largely ignored the falls on Monday with experts citing the widespread disbelief in the sustainability of recent iron ore levels.

"None of the miners were really pricing in the previous iron ore price and so a reasonable amount was already pre-empted by the stock market," said Glyn Lawcock, head of resources research at UBS Australia. 

"But I'm a little surprised to be honest, I would have thought a fall of that magnitude might seen them give up a little bit of ground."

BHP Billiton has lifted 1.2 per cent to $24.87 a share as of lunchtime on Monday, while main rival Rio Tinto is also up 1.6 per cent to $60.97. Pure iron ore player Fortescue Metals suffered slightly and is trading down 0.4 per cent to $6.08. 

But while iron ore took a tumble on Friday, the price of coking coal shot up, as China scrambles to cover Australian supply disruptions caused by Cyclone Debbie.

On Monday, coal added to Friday's 34 per cent leap after the storm wiped out the railway lines from a series of Queensland producers, which account for half the world's seaborne trade in coking coal, used for making steel.  

"Rail services are slowing coming back online, but prices could lift above $US300 a tonne before settling back down again," said Vivek Dhar, commodities analyst at Commonwealth Bank of Australia.

"It will likely take another four weeks before coal infrastructure returns back to normal."

Whitehaven Coal enjoyed a sharp spike in early Monday trade, before fading away in the early afternoon.

While investors have been coming to terms with iron ore and coal's supply issues, oil markets have provided further support for Australian mining and energy stocks. 

The price of brent crude was firm on Monday, supported by strong demand and political uncertainty in Syria. Brent crude futures were at $US55.32 per barrel in late Monday's trade, up 0.2 per cent since Friday's close. 

ANZ bank said on Monday strong oil demand and "an unsettled global backdrop [is] leaving the market very finely balanced".

The combination of stronger coal and oil prices and the general market understanding that iron ore is unlikely to maintain its current levels, have provided widespread buying support for Australia's miners. 

Barclays maintains that iron ore is likely to continue its retreat, echoing what the Reserve Bank of Australia has said, as well as other banks and even mining companies. 

Concerns Chinese authorities may implement policies that curb steel consumption have plagued the market for a while, as well as further expansion in supply from Brazil and Australia and even China itself. 

The Australian Government has also added its voice to the chorus, with the Department of Industry, Innovation and Science on Friday issuing its own warning. 

"Growing supply, primarily from Australia and Brazil, is expected to steadily outpace demand growth over the rest of 2017," read a statement. Adding that ore may slump to $US55 in the fourth quarter of this year.