Corkite is a phosphate mineral in the beudantite subgroup of the alunite group. Corkite is the phosphate analogue of beudantite and with it, a complete solid solution range exists. Corkite will also form a solid solution with kintoreite.

Corkite is named after County Cork, Ireland; the location where the first notable amount was discovered in 1869.^[3] Like many of the other minerals in the beudantite group, corkite is a relatively uncommon, secondary mineral that occurs in oxidation zones near hydrothermal base metal deposits.^[3] It occurs associated with pyromorphite, malachite, plumbojarosite, limonite and quartz.^[6]