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COMMON SHARES (Details Narrative) |  |  |  | 12 Months Ended |
--- | --- | --- | --- | --- | ---
Jun. 09, 2023 USD ($) shares | Apr. 28, 2023 USD ($) shares | Nov. 05, 2020 | Jun. 30, 2023 USD ($) shares | Jun. 30, 2022 USD ($) $ / shares shares | Jun. 30, 2023 $ / shares
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |
Warrants | shares |  | 314,465 |  |  |  |
Shares issue price |  | $ 2,000,000.0 |  |  |  |
Share issuance cost |  | $ 172,000 |  |  |  |
Stock price | $ / shares |  |  |  |  |  | $ 6.68
Description of warrants |  |  |  | The Company may elect to redeem the Public Warrants subject to certain conditions, in whole and not in part, at a price of $0.01 per Public Warrant if (i) 30 days’ prior written notice of redemption is provided to the holders, (ii) the last reported sale price of the Common Shares equals or exceeds approximately $16.10 per share (as adjusted for stock splits, stock dividends, reorganizations, recapitalizations and the like) for any 20 trading days within a 30-trading day period ending on the third business day prior to the date on which the Company sends the notice of redemption to the warrant holders |  |
GXII Public Warrants [Member] |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |
Warrants traded prior to the closing | shares |  |  |  | 9,999,959 |  |
GXII Private Warrants [Member] |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |
Warrants traded prior to the closing | shares |  |  |  | 5,666,667 |  |
Long TermIncentive Plan [Member] |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |
Description of amended plan |  |  | Subject to adjustment as described in the 2017 Amended Long-Term Incentive Plan, the aggregate number of Common Shares that may be reserved for issuance to participants under the 2017 Amended Long-Term Incentive Plan, together with all other security-based compensation arrangements of the Company, may not exceed 10% of the issued and outstanding Common Shares from time to time, and the Common Shares reserved for issuance upon settlement of share units will not exceed 5% of the issued and outstanding Common Shares from time to time. The 2017 Amended Long-Term Incentive Plan limits the maximum number of Common Shares issued to insiders (as defined under TSX rules for this purpose) within any one-year period, or issuable to insiders at any time, in the aggregate, under all security-based compensation arrangements (including the 2017 Amended Long-Term Incentive Plan) to 10% of the then issued and outstanding Common Shares. |  |  |
Warrant [Member] |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |
Description of warrants |  |  |  | Each NioCorp Assumed Warrant entitles the holder to the right to purchase 1.11829212 Common Shares at an exercise price of $11.50 per 1.11829212 Common Shares (subject to adjustments for stock splits, stock dividends, reorganizations, recapitalizations and the like). |  |
Canada, Dollars |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |
Total intrinsic value |  |  |  | $ 1,592 |  |
Private Placement [Member] | Canada, Dollars |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |
Warrants | shares |  |  |  |  | 498,103 |
Price per unit | $ / shares |  |  |  |  | $ 0.96 |
Gross proceeds |  |  |  |  | $ 4,800,000 |
Shares price | $ / shares |  |  |  |  | $ 1.10 |
Private Placement [Member] | Canada, Dollars | Warrant [Member] |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |
Warrants | shares |  |  |  |  | 6,510 |
Gross proceeds |  |  |  |  | $ 18 |
Cash commissions |  |  |  |  | $ 62 |
Risk-free rate |  |  |  |  | 3.20% |
Expected volatility |  |  |  |  | 64.00% |
Expected life |  |  |  |  | 2 years |
Yorkville Convertible Debt Financing Agreement [Member] |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |
Warrants | shares | 100,000 |  |  |  |  |
Share issuance cost | $ 13,000 |  |  |  |  |

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