Cal. Civ. Code § 883.110

As used in this chapter, “mineral right” means an interest in minerals, regardless of character, whether fugacious or nonfugacious, organic or inorganic, that is created by grant or reservation, regardless of form, whether a fee or lesser interest, mineral, royalty, or leasehold, absolute or fractional, corporeal or incorporeal, and includes express or implied appurtenant surface rights.