Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2016

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, 2016
Assets:
Cash and cash equivalents	$	2,588	$	—	$	—	$	2,588
Trade accounts receivable		380		—		—		380
Short-term investments		334		—		—		334
	$	3,302	$	—	$	—	$	3,302
Liabilities:
Warrant liability - related party	$	—	$	—	$	976	$	976
Warrant liability		—		—		922		922
	$	—	$	—	$	1,898	$	1,898
At December 31, 2015
Assets:
Cash and cash equivalents	$	4,077	$	—	$	—	$	4,077
Trade accounts receivable		546		—		—		546
Short-term investments		72		—		—		72
	$	4,695	$	—	$	—	$	4,695
Liabilities:
Warrant liability - related party	$	—	$	—	$	117	$	117
Warrant liability		—		—		93		93
Derivative liability - related party		—		—		488		488
	$	—	$	—	$	698	$	698

Schedule of significant inputs to the valuation model

	December 31,		December 31,
	2016		2015
Company's ending stock price	$	0.58	$	0.20
Company's stock volatility		110%		85%
Applicable risk free interest rate		1.39%		1.48%

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, 2015	$	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
Conversion of Sentient Loan (see Note 10)		—		(488)
Change in estimated fair value		1,688		—
Ending balance at December 31, 2016	$	1,898	$	—

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