(b) “Mineral” includes:

(1) Gas;

(2) Oil and oil shale;

(3) Coal;

(4) Gaseous, liquid, and solid hydrocarbons;

(5) Cement materials, sand and gravel, road materials, and building stone;

(6) Chemical substances;

(7) Gemstone, metallic, fissionable, and nonfissionable ores; and

(8) Colloidal and other clay, steam, and geothermal resources.

(c) “Mineral interest” means an interest in a mineral estate, however created and regardless of form, whether absolute or fractional, divided or undivided, corporeal or incorporeal, including a fee simple or any lesser interest or any kind of royalty, production payment, executive right, nonexecutive right, leasehold, or lien in minerals, regardless of character.

(d) “Severed mineral interest” means a mineral interest that is severed from the interest in the surface estate overlying the mineral interest.

(e) “Surface estate” means an interest in the estate overlying a mineral interest.

(f) (1) “Surface owner” means any person vested with a whole or undivided fee simple interest or other freehold interest in the surface estate.

(2) “Surface owner” does not include the owner of a right-of-way, easement, or leasehold on the surface estate.

(g) (1) “Unknown or missing owner” means any person vested with a severed mineral interest whose present identity or location cannot be determined:

(i) From the records of the county where the severed mineral interest is located; or

(ii) By diligent inquiry in the vicinity of the owner’s last known place of residence.

(2) “Unknown or missing owner” includes the heirs, successors, or assignees of an unknown or missing owner.