5. Inventories

3 Months Ended

Mar. 31, 2021

Inventory Disclosure [Abstract]

Inventories

Inventories at March 31, 2021 and December 31, 2020 consisted primarily of finished antimony products, antimony metal, antimony ore, and finished zeolite products that are stated at the lower of first-in, first-out cost or estimated net realizable value. Finished antimony products, antimony metal and finished zeolite products costs include raw materials, direct labor and processing facility overhead costs and freight. Inventories at March 31, 2021 and December 31, 2020 are as follows:

	March 31, 2021		December 31, 2020
Antimony Metal	$	25,238	$	268,100
Antimony Oxide		360,566		67,377
Antimony Ore		167,945		95,880
Total antimony		553,749		431,357
Zeolite		164,001		218,856
	$	717,750	$	650,213

Antimony oxide inventory consisted of finished product oxide held at the Company's plants in Montana and Mexico. Antimony concentrates and ore were held primarily at sites in Mexico and are essentially raw material. The Company's zeolite inventory consists of salable zeolite material.

At March 31, 2021 and December 31, 2020, the antimony inventory in Mexico was valued at estimated net realizable value.