Property, Plant and Equipment, Net (Tables)

9 Months Ended

Sep. 30, 2021

Property, Plant and Equipment, Net

Schedule of components of property, plant and equipment

	September 30,		December 31,
	2021		2020
	(in thousands)
Mineral properties	$	9,353	$	9,353
Exploration properties		2,418		2,418
Royalty properties		200		200
Buildings		3,807		3,755
Mining equipment and machinery		17,409		16,135
Other furniture and equipment		1,319		890
Construction in progress		—		259
Asset retirement cost		894		948
		35,400		33,958
Less: Accumulated depreciation and amortization		(28,879)		(28,438)
	$	6,521	$	5,520