At Surmont, instead of open-pit mining, the bitumen is melted out of the ground by injecting steam.

FORBES: Total Drops $1 Billion In Oil Sands Grab

The geology in Texas allows for a mining procedure called "in situ" recovery, cheaper than traditional seam or open-pit mining.

FORBES: Energy & Genius

The big prize here is a 20% stake in the Fort Hills oil sands project, an open-pit mining operation targeting 3.4 billion barrels of bitumen.

FORBES: Total Drops $1 Billion In Oil Sands Grab

The delays were caused by new Argentine import restrictions, which the company said has hindered its ability to purchase necessary spare parts in-country to keep all open-pit mining equipment in continuous operation.

FORBES: Pan American Silver Anticipates Navidad Study By Year-End; Encouraged By Argentine Politics

De Beers is active in every category of industrial diamond mining: open-pit, underground, large-scale alluvial, coastal and deep sea.

FORBES: Anglo American Receives Final Regulatory Approval for De Beers Acquisition