Summary of Significant Accounting Policies (Policies)	3 Months Ended
Sep. 30, 2013
Accounting Policies [Abstract]
Management Estimates	Management Estimates. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Cash Equivalents	Cash Equivalents. Cash equivalents are considered to be highly liquid securities having an original maturity of 90 days or less at the date of acquisition.
Revenue Recognition	Revenue Recognition. CORE has yet to realize any revenues. Expenses are presented on the accrual basis of accounting.
Capitalized Costs	Mineral Properties. The amount capitalized includes costs paid to acquire mineral property interests as well as the costs paid for federal and state of Alaska unpatented mining claims. Exploration costs are expensed as incurred. Development costs are expensed as incurred until the Company obtains proven and probable reserves within its commercially minable properties. Costs of abandoned projects are charged to earnings upon abandonment. Any properties determined to be impaired are written-down to their estimated fair value. The Company periodically evaluates whether events or changes in circumstances indicate that the carrying value of mineral property interests and any related property, plant and equipment may not be recoverable.
Common Stock	Common Stock. Our certificate of incorporation authorizes us to issue up to 30,000,000 shares of common stock, par value $0.01. As of September 30, 2013, the Company had 3,750,394 shares of common stock issued and outstanding, all of which were fully paid and non-assessable. Holders of common stock are entitled to one vote for each share held of record on all matters to be voted on by stockholders and are not entitled to cumulative voting for the election of directors. Upon the liquidation, dissolution or winding up of our business, after payment of all liabilities and payment of preferential amounts to the holders of preferred stock, if any, the shares of common stock are entitled to share equally in our remaining assets. Pursuant to our certificate of incorporation, no stockholder has any preemptive rights to subscribe for our securities. The common stock is not subject to redemption. The Company’s equity structure for all periods prior to November 29, 2010 was retroactively adjusted to reflect the equity structure of the Company after November 29, 2010.
Stock-Based Compensation	Stock-Based Compensation. The Company applies the fair value method of accounting for stock-based compensation. Under this method, compensation cost is measured at the grant date based on the fair value of the award and is recognized over the award vesting period. The Company classifies the benefits of tax deductions in excess of the compensation cost recognized for the options (excess tax benefit) as financing cash flows. The fair value of each award is estimated as of the date of grant using the Black-Scholes option-pricing model.
Reclassifications	Reclassifications. Certain prior period amounts have been reclassified to conform to current year presentation. These reclassifications were not material and had no effect on cash flows or net loss.
Income Taxes	Income Taxes. The Company follows the liability method of accounting for income taxes under which deferred tax assets and liabilities are recognized for the future tax consequences of (i) temporary differences between the tax basis of assets and liabilities and their reported amounts in the financial statements and (ii) operating loss and tax credit carry-forwards for tax purposes. Deferred tax assets are reduced by a valuation allowance when, based upon management’s estimates, it is more likely than not that a portion of the deferred tax assets will not be realized in a future period. The Company recognized a full valuation allowance as of September 30, 2013 and June 30, 2013 and has not recognized any tax provision or benefit for any of the periods. The Company reviews its tax positions quarterly for tax uncertainties. The Company did not have any uncertain tax positions as of September 30, 2013 or June 30, 2013.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements We have reviewed all recently issued, but not yet effective, accounting pronouncements and do not believe that the future adoption of any such pronouncements will cause a material impact on our financial condition or the results of our operations.

Summary of Significant Accounting Policies (Policies)

3 Months Ended

Sep. 30, 2013

Management Estimates. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Cash Equivalents

Cash Equivalents. Cash equivalents are considered to be highly liquid securities having an original maturity of 90 days or less at the date of acquisition.

Revenue Recognition

Revenue Recognition. CORE has yet to realize any revenues. Expenses are presented on the accrual basis of accounting.

Capitalized Costs

Mineral Properties. The amount capitalized includes costs paid to acquire mineral property interests as well as the costs paid for federal and state of Alaska unpatented mining claims. Exploration costs are expensed as incurred. Development costs are expensed as incurred until the Company obtains proven and probable reserves within its commercially minable properties. Costs of abandoned projects are charged to earnings upon abandonment. Any properties determined to be impaired are written-down to their estimated fair value. The Company periodically evaluates whether events or changes in circumstances indicate that the carrying value of mineral property interests and any related property, plant and equipment may not be recoverable.

Common Stock

Common Stock. Our certificate of incorporation authorizes us to issue up to 30,000,000 shares of common stock, par value $0.01. As of September 30, 2013, the Company had 3,750,394 shares of common stock issued and outstanding, all of which were fully paid and non-assessable. Holders of common stock are entitled to one vote for each share held of record on all matters to be voted on by stockholders and are not entitled to cumulative voting for the election of directors. Upon the liquidation, dissolution or winding up of our business, after payment of all liabilities and payment of preferential amounts to the holders of preferred stock, if any, the shares of common stock are entitled to share equally in our remaining assets. Pursuant to our certificate of incorporation, no stockholder has any preemptive rights to subscribe for our securities. The common stock is not subject to redemption. The Company’s equity structure for all periods prior to November 29, 2010 was retroactively adjusted to reflect the equity structure of the Company after November 29, 2010.

Stock-Based Compensation

Stock-Based Compensation. The Company applies the fair value method of accounting for stock-based compensation. Under this method, compensation cost is measured at the grant date based on the fair value of the award and is recognized over the award vesting period. The Company classifies the benefits of tax deductions in excess of the compensation cost recognized for the options (excess tax benefit) as financing cash flows. The fair value of each award is estimated as of the date of grant using the Black-Scholes option-pricing model.

Reclassifications

Reclassifications. Certain prior period amounts have been reclassified to conform to current year presentation. These reclassifications were not material and had no effect on cash flows or net loss.

Income Taxes

Income Taxes. The Company follows the liability method of accounting for income taxes under which deferred tax assets and liabilities are recognized for the future tax consequences of (i) temporary differences between the tax basis of assets and liabilities and their reported amounts in the financial statements and (ii) operating loss and tax credit carry-forwards for tax purposes. Deferred tax assets are reduced by a valuation allowance when, based upon management’s estimates, it is more likely than not that a portion of the deferred tax assets will not be realized in a future period. The Company recognized a full valuation allowance as of September 30, 2013 and June 30, 2013 and has not recognized any tax provision or benefit for any of the periods. The Company reviews its tax positions quarterly for tax uncertainties. The Company did not have any uncertain tax positions as of September 30, 2013 or June 30, 2013.

Recently Issued Accounting Pronouncements

We have reviewed all recently issued, but not yet effective, accounting pronouncements and do not believe that the future adoption of any such pronouncements will cause a material impact on our financial condition or the results of our operations.