When you're a leading global mining company with a an $81.5 billion market cap, I guess that helps to make you hard as a rock in certain respects.

The disastrous headlines and painful numbers keep pouring out of mining giant Rio Tinto (NYSE:RIO), with the latest year-end earnings report besmirched by a $2.99 billion net loss against a prior-year gain of $5.83 billion. Key to the damage was an embarrassing $14 billion in impairment charges relating to the company's aluminum business and coal assets in Mozambique. Its stock, meanwhile, continues to poke around with unabated strength near a seemingly incongruous 52-week high.

The damaging rhetoric from Mongolia earlier this month -- in which President Tsakhia Elbegdorj demanded a greater role for his government in overseeing the massive Oyu Tolgoi joint venture with Turquoise Hill Resources (NYSE:TRQ) -- would have been enough to decimate the stock of a lesser company. The leader also expressed dismay that the cost to complete construction and expansion of the project has increased by nearly $10 billion -- from an earlier projection of $14.6 billion to an eye-popping $24.4 billion. 

We've witnessed firsthand the wreckage that similar bouts of cost escalation have cast upon major gold miner Barrick Gold (NYSE:GOLD), and we averted our eyes to the collapsed share price of Thompson Creek Metals (NASDAQOTH:TCPTF) as the Mt. Milligan budget spiraled out of control. But Rio Tinto's stock just keeps marching along.

We've seen Cliffs Natural Resources (NYSE:CLF) taken to the woodshed -- and rightfully so, I might add -- for adding share dilution and a slashed dividend to the pain of a major asset impairment. Shares of Kinross Gold bear the unmistakable scars of asset impairments totaling 79% of a disturbingly recent acquisition . But when Rio Tinto makes $14 billion disappear, the market barely bats an eye. Like Kinross' Tye Burt, Rio Tinto's Tom Albanese has been replaced as a consequence of failed acquisitions. But how on earth does the stock fail to register such a grand mea culpa?

The explanation for this defiant strength in the shares of Rio Tinto is twofold. For starters, the company's iron ore business remains enormously profitable, delivering a 44% return on operating assets over the course of 2012 (even as average iron ore prices declined by 23%) . Second, with the slate essentially wiped clean from yesterday's multiple missteps, new CEO Sam Walsh will now have the opportunity to liquidate non-performing assets and book solid-looking gains in the process. Just last December, the company offloaded some non-core copper assets in South Africa for $373 million, and there's plenty more where that came from in terms of opportunities for monetization of non-core assets.