Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2016

Schedule of components of property, plant and equipment

	December 31,
	2016		2015
	(in thousands)
Mineral properties	$	9,352	$	9,630
Exploration properties		2,518		2,518
Royalty properties		200		200
Buildings		4,386		4,377
Mining equipment and machinery		16,351		16,998
Other furniture and equipment		952		841
Asset retirement cost		992		1,285
		34,751		35,849
Less: Accumulated depreciation and amortization		(25,516)		(24,724)
	$	9,235	$	11,125

Velardena properties

Schedule of details of components of the impairment of long lived assets

			Impairment
	Gross Value		Charge		Gross Value
	Prior to		Minerals		After
	Impairment at		Properties		Impairment at
	Sept. 30, 2015		Asset Group		Sept. 30, 2015
	(in thousands)
Mineral properties	$	21,936	$	12,306	$	9,630
Exploration properties		3,001		458		2,543
Royalty properties		200		—		200
Buildings		4,377		—		4,377
Mining equipment and machinery		17,181		—		17,181
Other furniture and equipment		841		—		841
Asset retirement cost		1,702		417		1,285
	$	49,238	$	13,181	$	36,057