Adjective
Formed or crystallized at depths the earth's surface; -- said of granite, gneiss, and other rocks, whose crystallization is believed of have taken place beneath a great thickness of overlying rocks. Opposed to epigene.
Source: Webster's dictionaryAlthough the features of turquoise occurrences are consistent with a secondary or supergene origin, some sources refer to a hypogene origin. Source: Internet
The hypogene hypothesis holds that the aqueous solutions originate at significant depth, from hydrothermal processes. Source: Internet
This hypogene process is applicable to the original copper sulfide deposition; however, it is difficult to account for the many features of turquoise occurrences by a hypogene process. Source: Internet