Inventories

12 Months Ended

Dec. 31, 2019

Inventory Disclosure [Abstract]

Inventories

Inventories:

The following table provides a breakdown of inventories at December 31, 2019 and 2018 (in thousands):

	December 31,
	2019		2018
Finished goods(a)	$	495,639	$	482,355
Raw materials and work in process(b)	205,781		158,290
Stores, supplies and other	67,564		59,895
Total	$	768,984	$	700,540

(a) Included $44.3 million and $104.3 million at December 31, 2019 and 2018, respectively, of chemical grade spodumene in our Lithium segment, most of which is converted to battery-grade products either internally or through our tolling agreements.

(b) Included $109.3 million and $71.4 million at December 31, 2019 and 2018, respectively, of work in process in our Lithium segment.

Approximately 10% of our inventories are valued using the last-in, first-out (“LIFO”) method at December 31, 2019 and 2018. The portion of our domestic inventories stated on the LIFO basis amounted to $78.7 million and $69.2 million at December 31, 2019 and 2018, respectively, which are below replacement cost by approximately $30.8 million and $32.8 million, respectively.