5. Investments

The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. Short-term investments include investments with maturities greater than 3 months, but not exceeding 12 months. Long-term investments include investments with maturities greater than 12 months.

The Company determines the appropriate classification of its investments in debt and equity securities at the time of purchase and re-evaluates those classifications at each balance sheet date. Debt securities are classified as held to maturity when the Company has the intent and ability to hold the securities to maturity. Held to maturity debt securities are stated at amortized cost and include government agency and corporate obligations. Available for sale investments are marked to market at the end of each reporting period with changes in value recorded as a component of other comprehensive income (loss). If declines in value are deemed other than temporary, a charge is made to net income (loss) for the period. The Company invests only in government and corporate securities rated “investment grade” or better.

The following table summarizes the Company’s investments at December 31, 2012:

December 31, 2012	Cost			Estimated Fair Value		Carrying Value
Investments:
Short-term:
Warrant to purchase common stock	$		124	$	—	$	—
Available for sale common stock	$		207	$	242	$	242
Total available for sale	331			242		242
Total short term	$	331		$	242	$	242

The Company did not hold any investments at December 31, 2013. The available for sale common stock at December 31, 2012 consisted of 3.0 million shares of a junior mining company received during the third quarter 2012 related to the 2011 sale of the Company’s Paca Pulacayo property in Bolivia. During the first quarter 2013 all of the shares were sold for net proceeds of approximately $0.2 million resulting in a nominal loss recorded to interest and other expense.

At December 31, 2012, the Company held warrants to purchase common stock of a junior mining company which were acquired in a transaction related to the Company’s exploration activities. The warrants expired on January 6, 2013 and had a nominal carrying value of less than one thousand dollars at December 31, 2012.

Quoted market prices at December 31, 2012 were used to determine the fair values of the above investments. See Note 13 for further discussion on the fair value measurement techniques used by the Company to value the above investments.