I've eaten enough humble pie to serve an army lately, and I'm feeling rather stuffed. But Cliffs Natural Resources (NYSE:CLF) seems to think there's room in my Foolish belly for one more unsavory slice.

A looming $1 billion goodwill impairment charge -- relating to the miner's $5 billion acquisition of Canadian iron ore miner Consolidated Thompson in 2011 -- will leave a nasty stain on Cliffs' balance sheet when the company reports fourth-quarter earnings on Feb. 13. Two years ago, I wrongly praised the acquisition as "the stuff that strategic dreams are made of." I even went so far as to reference the mining industry's poor track record of injuring shareholders with overly aggressive acquisitions timed near the height of volatile commodity price cycles, and predicted that this particular deal would enjoy a "soft landing."

But, here in the aftermath of Cliffs' inglorious fall last October, and the company's "significant adjustments" to its 2013 operating plan announced in November, it became abruptly clear how wrong I had been. Faced with relentless cost pressures plaguing the entire industry, weakened iron ore market conditions, and also some material reassessment of long-term operating expectations for the project, Cliffs decided to delay completion of the phase two expansion at the Bloom Lake mine until at least early 2014.

The impaired valuation of Cliffs' 2011 acquisition now joins a most inglorious continuation of major miners' appalling track record of shareholder value destruction through aggressive acquisitions. Metallurgical coal competitor Walter Energy (OTC:WLTGQ) unleashed a $1.1 billion writedown in November, and global giant Rio Tinto (NYSE:RIO) sent its CEO packing just last week after revealing shameful impairments totaling $14 billion! The bulk of those charges stems from Rio Tinto's ill-timed and ill-fated acquisition of aluminum maker Alcan, reflecting persistent and severe weakness in that segment of the commodity complex as well. Iron ore major Vale (NYSE:VALE) itself will book a $1.3 billion impairment on its minority stake in Norwegian aluminum group Norsk Hydro, and analysts expect BHP Billiton (NYSE:BHP) to soon suffer multibillion-dollar impairments of its own relating to underperforming aluminum and nickel assets.

In total, Cliffs will book $1.4 billion in non-cash charges, including a $365 million hit relating to the pending sale of its stake in the Amapa iron ore project in Brazil. Unfortunately, I don't suspect this will mark an end to Cliffs' troubles, with the company's medium-term earnings outlook looking rather grim. I continue to view Cliffs Natural Resources as an unsuitable investment vehicle at this time, perceiving risk of further downside to the shares.