Income Tax - Schedule of Net Deferred Tax Asset (Details) - USD ($) |
Apr. 30, 2020 |
Apr. 30, 2019 |
|---|---|---|
| Income Tax Disclosure [Abstract] | ||
| Net operating loss carryover | $ 5,083,000 | $ 3,777,000 |
| Stock-based compensation | 2,019,000 | 1,753,000 |
| Capitalized exploration costs | 340,000 | 341,000 |
| Accrued remediation costs | 7,000 | 3,000 |
| Alternative minimum tax credit carryover | 438,000 | |
| Subtotal | 7,449,000 | 6,312,000 |
| Less: valuation allowance | (7,449,000) | (6,312,000) |
| Net deferred tax asset |
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible alternative minimum tax credit carryforwards. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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| X | ||||||||||
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from accrued liabilities. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of deferred tax liability attributable to taxable temporary differences from research and development costs. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- References No definition available.
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