INVENTORY AND LONG-TERM PARTS INVENTORY

12 Months Ended

Dec. 31, 2019

The following summarizes our inventory, recorded at the lower of weighted average cost or estimated net realizable value as of December 31, 2019, and 2018, respectively (in thousands):



	December 31,
	2019		2018
Finished goods product inventory	$	55,585	$	48,370
In-process mineral inventory	25,591		24,325
Total product inventory	81,176		72,695
Current parts inventory, net	13,044		9,351
Total current inventory, net	94,220		82,046
Long-term parts inventory, net	27,569		30,031
Total inventory, net	$	121,789	$	112,077

Parts inventories are shown net of any required allowances. During the years ended December 31, 2019, 2018, and 2017, we recorded charges of approximately $1.8 million, $1.7 million, and $6.4 million, respectively, as a result of routine assessments of the lower of weighted average cost or estimated net realizable value on our finished goods product inventory.