| Schedule of Property, Plant and Equipment and Depreciation and Depletion Expense |
The Company’s property, plant and equipment consisted of the following: | | | | | | | | | | | | | September 30, 2026 | | December 31, 2025 | | (in thousands) | | | Land and land improvements | $ | 136,179 | | | $ | 43,422 | | | Buildings and building improvements | 102,026 | | | 101,564 | | | Machinery and equipment | 923,554 | | | 756,202 | | | Assets under construction | 509,337 | | | 302,935 | | | Mineral rights | 438,395 | | | 438,395 | | | Property, plant and equipment, gross | 2,109,491 | | | 1,642,518 | | | Less: Accumulated depreciation and depletion | (351,542) | | | (272,701) | | | Property, plant and equipment, net | $ | 1,757,949 | | | $ | 1,369,817 | |
The Company’s depreciation and depletion expenses, net of amounts capitalized into inventory, were as follows: | | | | | | | | | | | | | | | | | | | | | | | | | For the three months ended September 30, | | For the nine months ended September 30, | | (in thousands) | 2026 | | 2025 | | 2026 | | 2025 | Depreciation expense | $ | 22,434 | | | $ | 18,500 | | | $ | 62,552 | | | $ | 55,760 | | | Depletion expense | $ | 2,672 | | | $ | 3,580 | | | $ | 7,268 | | | $ | 7,748 | |
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