Property, Plant and Equipment, Net (Tables)

12 Months Ended

Dec. 31, 2021

Property, Plant and Equipment, Net

Schedule of components of property, plant and equipment

	December 31,		December 31,
	2021		2020
	(in thousands)
Mineral properties	$	9,353	$	9,353
Exploration properties		2,418		2,418
Royalty properties		200		200
Buildings		3,806		3,755
Mining equipment and machinery		17,477		16,135
Other furniture and equipment		1,328		890
Construction in progress		—		259
Asset retirement cost		1,057		948
		35,639		33,958
Less: Accumulated depreciation and amortization		(29,012)		(28,438)
	$	6,627	$	5,520