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v3.19.1

RELATED PARTY TRANSACTIONS (Details) - USD ($) |  | 1 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Jun. 30, 2019 | Jun. 30, 2019 | Jun. 30, 2016 | Dec. 31, 2018 | Dec. 31, 2017
Related Party Transaction [Line Items] |  |  |  |  |
Common stock, shares, outstanding (in shares) |  |  |  | 74,366,824 | 66,205,153
Testing permit and lease option agreement, accrued liability |  |  |  | $ 1,350,000 |
Royalty percentage of minerals recovered sold under minimum price threshold |  |  | 3.125% |  |
Mineral price per pound, low range |  |  | $ 65.00 |  |
Royalty percentage of minerals recovered sold between price thresholds |  |  | 6.25% |  |
Mineral price per pound, upper range |  |  | $ 95.00 |  |
Royalty percentage of minerals recovered sold above maximum price threshold |  |  | 7.50% |  |
Payments for royalties |  |  |  | $ 0 |
Mestena Sellers |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |
Common stock, shares, outstanding (in shares) |  |  |  | 4,303,032 |
Scenario, Forecast |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |
Testing permit and lease option agreement, payments | $ 1,350,000 |  |  |  |
Director |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |
Equity method, ownership percentage |  |  |  | 81.00% |
Proceeds from contributed capital |  |  |  | $ 0 |
Director | Leoncito Project, L.L.C. |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |
Testing permit and lease option agreement, percentage that may be paid in common shares |  |  | 50.00% |  |
Testing permit and lease option agreement, accrued liability |  |  |  | $ 500,000 |
Director | Scenario, Forecast | Leoncito Project, L.L.C. |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |
Testing permit and lease option agreement, payments |  | $ 600,000 |  |  |
Director | Mesteña LLC |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |
Sale of stock, number of shares issued in transaction (in shares) |  |  | 4,551,284 |  |
Director | United Nuclear |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |
Equity method, ownership percentage |  |  |  | 19.00% |

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