Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2015

Fair Value Measurements

Schedule of financial assets and liabilities at fair value by respective level of the fair value hierarchy

	Level 1		Level 2		Level 3		Total
	(in thousands)
At December 31, 2015
Assets:
Cash and cash equivalents	$	4,077	$	—	$	—	$	4,077
Trade accounts receivable	546		—		—		546
Marketable securities	72		—		—		72
	$	4,695	$	—	$	—	$	4,695
Liabilities:
Warrant liability	$	—	$	—	$	210	$	210
Derivative liability	—		—		488		488
	$	—	$	—	$	698	$	698
At December 31, 2014
Assets:
Cash and cash equivalents	$	8,579	$	—	$	—	$	8,579
Trade accounts receivable	—		—		—		—
	$	8,579	$	—	$	—	$	8,579
Liabilities:
Warrant liability	$	—	$	—	$	1,554	$	1,554
	$	—	$	—	$	1,554	$	1,554

Schedule of significant inputs to the valuation model

	December 31,
	2015			2014
Company’s ending stock price	$	0.20		$	0.54
Company’s stock volatility	85		%	90		%
Applicable risk free interest rate	1.48		%	1.60		%

Summary of change in fair value of the warrant liability

	Fair Value Measurements
	Using Significant Unobservable
	Inputs (level 3)
	Warrant Liabilities			Derivative Liability
	(in thousands)
Beginning balance at January 1, 2014	$	—		$	—
Adjustment to record 2012 warrants as a liability (Note 16)	163			—
Issuance of warrants	3,084			—
Change in estimated fair value	(1,693		)	—
Ending balance at December 31, 2014	$	1,554		$	—
Sentient Note, October 27, 2015	—			1,040
Change in estimated fair value	(1,344		)	(552		)
Ending balance at December 31, 2015	$	210		$	488

Summary of the Company's non-recurring fair value measurements

	Level 1		Level 2		Level 3		Total
	(in thousands)
At September 30, 2015
Assets:
Mineral properties	$	—	$	—	$	1,354	$	1,354
	$	—	$	—	$	1,354	$	1,354