Critical and Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2012

Critical and Significant Accounting Policies

Schedule of estimated useful lives of other plant and equipment for computation of depreciation using straight-line method

Buildings and improvements	5 to 25 years
Machinery and equipment	3 to 20 years
Furniture and fixtures	3 years

Exploration costs included in cost of product sold

Exploration costs are included in cost of product sold and consisted of the following for the years ended December 31 (in thousands):

	2012		2011		2010
Exploration Costs	$	1,671	$	484	$	156