GEOLOGÍA ESTRUCTURAL DE LA MINA.

The following table sets forth our cash and cash equivalents and capitalization as of December 31, 2008:

•

on an actual basis;

•

on a pro forma basis to reflect the optional conversion of all outstanding shares of Series A Convertible Preferred Stock into 44,805,437 shares of common stock and the reclassification of $27.1 million of the accreted value of the Series A Convertible Preferred Stock to accrued liabilities to reflect the payable due to holders of Series A Convertible Preferred Stock upon the optional conversion;

•

on a pro forma as adjusted basis to reflect:

(i)

the optional conversion of all outstanding shares of Series A Convertible Preferred Stock into 44,805,437 shares of common stock and the reclassification of $27.1 million of the accreted value of the Series A Convertible Preferred Stock to accrued liabilities to reflect the payable due to holders of Series A Convertible Preferred Stock upon the optional conversion;

the sale by us of 3,500,000 shares of common stock in this offering at an initial public offering price of $10.50 per share, after deducting underwriting discounts and commissions and estimated offering expenses payable by us of $8.5 million;

(iii)

the payment of the $27.1 million liability resulting from the optional conversion of Series A Convertible Preferred Stock;

(iv)

the exercise by selling stockholders of options to purchase an aggregate of 102,963 shares of common stock at a weighted average exercise price of $0.36 per share for total proceeds to us of $37,083;

(v)

the exercise by selling stockholders of warrants to purchase an aggregate of 426,217 shares of common stock at a weighted average exercise price of $2.14 per share for total proceeds to us of $910,103;

(vi)

the net issuance of 204,361 shares of common stock upon the cashless net exercise by selling stockholders of warrants to purchase an aggregate of 228,887 shares of common stock at a weighted average exercise price of $1.13 per share; and

(vii)

the amendment and restatement of our certificate of incorporation in connection with the closing of this offering, which will increase our authorized capital stock.

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You should read this table together with "Use of Proceeds," "Management's Discussion and Analysis of Financial Condition and Results of Operations," "Description of Capital Stock" and our consolidated financial statements, which are included elsewhere in this prospectus.

As of December 31, 2008 Actual Pro Forma Pro Forma as Adjusted (In thousands, except share and per

share data)

Cash and cash equivalents $ 56,483 $ 56,483 $ 58,629

Amount due to holders of Series A Convertible Preferred Stock upon optional conversion $ — $ 27,062 $ — Total indebtedness (including short-term and long-term leases and notes payable) $ 684 $ 684 $ 684 Series A Convertible Preferred Stock: $0.01 par value; 19,850,000 shares authorized,

19,778,333 shares issued and outstanding, actual; no shares authorized, issued and outstanding,

pro forma and pro forma as adjusted 27,062 — —

Stockholders' equity:

Undesignated preferred stock: $0.01 par value; no shares authorized, issued and outstanding, actual and pro forma; 20,000,000 shares authorized, no shares issued and outstanding, pro forma as adjusted

Common stock: $0.01 par value; 300,000,000 shares authorized, 3,335,089 shares issued and outstanding, actual; 300,000,000 shares authorized, 48,140,526 shares issued and outstanding, pro forma; 300,000,000 shares authorized, 52,374,067 shares issued and outstanding pro forma

as adjusted 33 481 524

Additional paid-in capital 1,703 1,255 30,420

Retained earnings 4,373 4,373 4,373

Total stockholders' equity 6,109 6,109 35,317

Total capitalization $ 33,855 $ 6,793 $ 36,001

The table above excludes the following shares:

1,577,890 shares of common stock issuable upon the exercise of warrants outstanding as of December 31, 2008, at a weighted average exercise price of $2.26 per share, on an actual and pro forma basis;

•

922,786 shares of common stock issuable upon the exercise of warrants outstanding as of December 31, 2008, at a weighted average exercise price of $2.59 per share, on a pro forma as adjusted basis;

•

8,827,585 shares of common stock issuable upon the exercise of options outstanding as of December 31, 2008, at a weighted average exercise price of $0.37 per share, on an actual and pro forma basis; and

•

8,724,622 shares of common stock issuable upon the exercise of options outstanding as of December 31, 2008, at a weighted average exercise price of $0.38 per share, on a pro forma as adjusted basis.

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DILUTION

If you invest in our common stock, your investment will be diluted to the extent of the difference between the initial public offering price per share of our common stock and the net tangible book value per share of our common stock after this offering. We calculate net tangible book value per share by calculating our total assets less intangible assets and total liabilities, and dividing it by the number of outstanding shares of common stock.

As of December 31, 2008, our net tangible book value was $31.3 million, or $9.38 per share of common stock, and our pro forma net tangible book value, after giving effect to the optional conversion of all outstanding shares of Series A Convertible Preferred Stock into 44,805,437 shares of common stock and the payment of the accreted value of $27.1 million on the Series A Convertible Preferred Stock to the holders thereof in cash, was $4.2 million, or $0.09 per share of common stock. After giving effect to (i) the sale by us of 3,500,000 shares of common stock in this offering at an initial public offering price of $10.50 per share, after deducting underwriting discounts and commissions and estimated offering expenses payable by us of $8.5 million, (ii) the exercise by selling stockholders of options to purchase an aggregate of 102,963 shares of common stock at a weighted average exercise price of $0.36 per share for total proceeds to us of $37,083, (iii) the exercise by selling stockholders of warrants to purchase an aggregate of 426,217 shares of common stock at a weighted average exercise price of $2.14 per share for total proceeds to us of $910,103 and (iv) the net issuance of 204,361 shares of common stock upon the cashless net exercise by selling stockholders of warrants to purchase an aggregate of 228,887 shares of common stock at a weighted average exercise price of $1.13 per share, our pro forma as-adjusted net tangible book value as of December 31, 2008 would have been $33.4 million, or $0.64 per share of common stock. This represents an immediate increase in net tangible book value of $0.55 per share to our existing stockholders and an immediate dilution of $9.86 per share to purchasers of common stock in this offering. The following table illustrates this dilution on a per share basis:

Initial public offering price per share $10.50

Net tangible book value per share as of December 31, 2008 $ 9.38

Decrease in net tangible book value per share attributable to the conversion of all outstanding shares of

Series A Convertible Preferred Stock as of December 31, 2008 (9.29)

Pro forma net tangible book value per share as of December 31, 2008 0.09

Increase in pro forma net tangible book value per share attributable to this offering 0.55

Pro forma as-adjusted net tangible book value per share after this offering 0.64

Dilution per share to new investors $ 9.86

The following table summarizes as of December 31, 2008, after giving effect to (i) the conversion of all outstanding shares of Series A Convertible Preferred Stock into common stock and (ii) the exercise of warrants and options by the selling stockholders in this offering as described above, the differences between the number of shares of common stock purchased from us, the aggregate cash consideration paid and the average price per share paid by existing stockholders and new investors purchasing shares of common stock from us in this offering.

Shares Purchased Total Consideration Number Percent Amount Percent

Average Price Per Share Existing stockholders 48,874,067 93.3% $24,909,983 40.4% $ 0.51 New investors 3,500,000 6.7 36,750,000 59.6 $ 10.50 Total 52,374,067 100% $61,659,983 100% 42