property is placed in service shall include an allowance equal to 100 percent of the adjusted basis of such property, or (ii) if such property was placed in service before the date of enactment of this subsection, the depreciation deduction provided by section 167(a) for the first taxable year beginning after such date shall include an allowance equal to 100 percent of the adjusted basis of such property, and (B) the adjusted basis of such property shall be reduced by the amount of such deduction before computing the amount otherwise allowable as a depreciation deduction under this chapter for such taxable year and any subsequent taxable year. (2) Qualified real property For purposes of this subsection, the term qualified real property means any nonresidential real property which is directly involved in extracting critical minerals and metals (as defined in subsection (k)(11)(B)) from deposits in the United States. . (b) Effective date The amendment made by this section shall apply to taxable years beginning after December 31, 2019. 4. Deduction for purchase of critical minerals and metals extracted within the United States (a) In general Part VI of subchapter B of chapter 1 of the Internal Revenue Code of 1986 is amended by inserting after section 176 the following new section: 177. Deduction for purchase of critical minerals and metals extracted within the United States (a) Allowance of deduction There shall be allowed as a deduction for the taxable year an amount equal to 200 percent of the cost paid or incurred by the taxpayer for the purchase or acquisition of critical minerals and metals (as defined in section 168(k)(11)(B)) which have been extracted from deposits in the United States. (b) Application with other deductions No deduction shall be allowed under any other provision of this chapter with respect to any expenditure with respect to which a deduction is allowed or allowable under this section to the taxpayer. . (b) Conforming amendment The table of sections for part VI of subchapter B of chapter 1