PROPERTY, PLANT AND EQUIPMENT

12 Months Ended

Dec. 31, 2021

Property, Plant and Equipment [Abstract]

NOTE 6 - PROPERTY, PLANT AND EQUIPMENT

The following table indicates the carrying value of each of the major classes of our depreciable assets:


	(In Millions)
	December 31,
	2021		2020
Land, land improvements, and mineral rights	$	1,291	$	1,213
Buildings	889		703
Equipment	8,709		6,786
Other	229		151
Construction in progress	408		1,364
Total property, plant and equipment1	11,526		10,217
Allowance for depreciation and depletion	(2,340)		(1,474)
Property, plant, and equipment, net	$	9,186	$	8,743

1 Includes right-of-use assets related to finance leases of $411 million and $361 million as of December 31, 2021 and 2020, respectively.

We recorded depreciation expense of $848 million, $298 million and $77 million for the years ended December 31, 2021, 2020 and 2019, respectively.

We recorded capitalized interest into property, plant and equipment of $6 million, $53 million and $25 million during the years ended December 31, 2021, 2020 and 2019, respectively.

The net book value of the mineral and land rights are as follows:


	(In Millions)
	December 31,
	2021		2020
Mineral rights:
Cost	$	780	$	773
Depletion	(187)		(142)
Net mineral rights	$	593	$	631

Land rights	$	406	$	361

We recorded depletion expense of $46 million, $8 million and $8 million for the years ended December 31, 2021, 2020, and 2019, respectively.