Section 15-1201 - Definitions(a) In this subtitle the following words have the meanings indicated.(b) "Mineral" includes:(4) Gaseous, liquid, and solid hydrocarbons;(5) Cement materials, sand and gravel, road materials, and building stone;(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.