| In millions, except per share items | Dec-31-22 | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 |
| | 10-K | 10-K | 10-K | 10-K | 10-K/A | 10-K | 10-K | 10-K |
| Revenues | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Cost of goods sold | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Gross profit | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Gross margin | | | | | | | | |
| Selling, general and administrative [+] | 9.9 | 8.9 | 5.7 | 4.5 | 7.0 | 6.6 | 7.7 | 7.5 |
| General and administrative | 9.9 | 8.9 | 5.7 | 4.5 | 7.0 | 6.6 | 7.7 | 7.5 |
| Research and development | 1.1 | 6.0 | 4.0 | 0.1 | | | | |
| Other operating expenses [+] | 0.8 | -0.9 | 2.7 | 0.3 | -7.3 | 0.8 | 10.7 | 4.4 |
| Exploration expenses | -0.8 | -1.1 | | -0.3 | | -4.6 | | |
| EBITDA [+] | -11.8 | -14.0 | -12.5 | -4.8 | | -7.4 | -18.4 | |
| EBITDA growth | -15.2% | 11.7% | 158.5% | -1551.7% | -104.5% | -59.7% | 59.3% | 47.2% |
| EBITDA margin | | | | | | | | |
| Depreciation and amortization | 0.1 | 0.0 | -0.1 | 0.1 | | 0.1 | 0.2 | |
| EBIT [+] | -12.0 | -14.0 | -12.4 | -4.9 | 0.3 | -7.5 | -18.6 | -11.5 |
| EBIT growth | -14.3% | 12.3% | 153.6% | -1573.6% | -104.4% | -59.5% | 61.4% | 41.3% |
| EBIT margin | | | | | | | | |
| Non-recurring items [+] | 0.1 | 2.2 | 1.5 | 1.4 | 0.3 | 12.4 | 1.7 | 1.0 |
| Asset impairment | | | | | | 11.4 | 1.7 | 1.0 |
| Legal settlement | 0.1 | 2.2 | 1.5 | 1.4 | | | | |
| Interest expense, net [+] | | | | -0.3 | | -0.6 | 2.8 | 2.6 |
| Interest expense | | | | | | | 2.8 | 2.6 |
| Interest income | | | | 0.3 | | 0.6 | | |
| Other income (expense), net [+] | 1.0 | 0.0 | 0.0 | 0.0 | | 0.1 | 3.5 | 0.0 |
| Acquisition-related costs | | | | | | | | -3.0 |
| Gain (loss) on sale of assets | | | -2.7 | 0.7 | | 4.9 | | |
| Unrealized gain (loss) on marketable securities | | | | -0.7 | | | | |
| Gain (loss) on debt retirement | | | | | | 0.0 | -3.3 | |
| Other non-operating income | | | | | | | 0.1 | |
| Other | 1.0 | 0.0 | 0.0 | 0.0 | -0.4 | 0.0 | 0.1 | 0.0 |
| Pre-tax income | -11.1 | -16.1 | -13.9 | -6.0 | 0.0 | -19.3 | -19.6 | -15.1 |
| Income taxes | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Tax rate | 0.0% | 0.0% | 0.0% | 0.0% | | 0.0% | 0.0% | 0.0% |
| Net income | -11.1 | -16.1 | -23.6 | -10.6 | 0.0 | -19.3 | -19.6 | -15.1 |
| Net margin | | | | | | | | |
| |
| Basic EPS [+] | ($0.25) | ($0.49) | ($2.68) | ($5.39) | | ($0.78) | ($3.73) | ($5.63) |
| Growth | -49.9% | -81.5% | -50.3% | | | -79.1% | -33.7% | 6.6% |
| Diluted EPS [+] | ($0.25) | ($0.49) | ($2.68) | ($5.39) | | ($0.78) | ($3.73) | ($5.63) |
| Growth | -49.9% | -81.5% | -50.3% | | | -79.1% | -33.7% | 6.6% |
| |
| Shares outstanding (basic) [+] | 44.9 | 32.7 | 8.8 | 2.0 | | 24.7 | 5.3 | 2.7 |
| Growth | 37.5% | 271.1% | 348.7% | | | 371.0% | 95.2% | 33.0% |
| Shares outstanding (diluted) [+] | 44.9 | 32.7 | 8.8 | 2.0 | | 24.7 | 5.3 | 2.7 |
| Growth | 37.5% | 271.1% | 348.7% | | | 371.0% | 95.2% | 33.0% |
| |
| EBIT is a non-GAAP figure that excludes all non-recurring expenses: restructuring costs, asset impairments, IPR&D writeoffs, and other unusual charges. |