Inventory

The carrying value of product inventory was as follows:



(in millions)	September 30, 2013		December 31, 2012
Finished product	$	42.2	$	53.5
Work-in-process	29.3		32.3
Stockpiled material	27.3		25.0
	$	98.8	$	110.8

As of September 30, 2013, the carrying value of TCM's in process and finished product inventory was $98.8 million, net of lower-of-cost-or-market write downs. Total write downs were $13.7 million and $27.6 million for the three and nine months ended September 30, 2013, respectively. Inventory write downs in the accompanying Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) for the three and nine months ended September 30, 2013 included $5.4 million and $17.0 million, respectively, of inventory write downs in operating expenses and $1.0 million and $3.3 million, respectively, of inventory write downs in depreciation, depletion and amortization. In addition, for the three and nine months ended September 30, 2013, $7.3 million of inventory write downs are included in start-up costs, of which $0.9 million are related to depreciation, depletion, and amortization.

As of September 30, 2012, the carrying value of TCM's in process and finished product inventory exceeded the market value. Total write downs were $29.5 million and $57.2 million for the three and nine months ended September 30, 2012, respectively. Inventory write downs in the accompanying Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) for the three and nine months ended September 30, 2012 included $21.6 million and $42.5 million, respectively, of inventory write downs in operating expenses and $7.9 million and $14.7 million, respectively, of inventory write downs in depreciation, depletion and amortization.