What is "plumbogummite"

n. (context mineral English) A trigonal-hexagonal scalenohedral mineral containing aluminum, hydrogen, lead, oxygen, and phosphorus.

Plumbogummite is a rare secondary lead phosphate mineral, belonging to the alunite supergroup of minerals, crandallite subgroup. Some other members of this subgroup are:

• Crandallite, CaAl(PO)(OH)·HO, where calcium replaces lead
• Goyazite, SrAl(PO)(OH)·HO, where strontium replaces lead
• Philipsbornite, PbAl(AsO)(OH)·HO, where the arsenate group AsO replaces the phosphate group PO

Plumbogummite was discovered in 1819 and named in 1832 from the Latin "plumbum" for lead, and "gummi" for gum, in allusion to its lead content and appearance, which at times resembles coatings of gum.