Crandallite group

Crandallite is a calcium aluminium basic phosphate mineral. It has ideal formula . Crandallite was named after Milan L. Crandall Jr, who worked for Knight Syndicate. This mineral is found in laterite and in alteration products of phosphate rich pegmatites.

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, CaAl3(PO4)2(OH)5·H2O, where calcium replaces lead Goyazite, SrAl3(PO4)2(OH)5·H2O, where strontium replaces lead Philipsbornite, PbAl3(AsO4)2(OH)5·H2O, where the arsenate group AsO4 replaces the phosphate group PO4

Segnitite is a lead iron(III) arsenate mineral. Segnitite was first found in the Broken Hill ore deposit in Broken Hill, New South Wales, Australia. In 1991, segnitite was approved as a new mineral. Segnitite has since been found worldwide near similar locality types where rocks are rich in zinc and lead especially. it was named for Australian mineralogist, gemologist and petrologist Edgar Ralph Segnit. The mineral was named after E. R. Segnit due to his contributions to Australian mineralogy.

Zaïrite is a phosphate mineral with the chemical formula Bi(Fe3+,Al)3[(OH)6|(PO4)2]. The name was given from where it was locally discovered in Eta-Etu, Kivu, Congo (Zaïre) in 1975.

Florencite-(Sm) is a very rare mineral of the plumbogummite group (alunite supergroup) with simplified formula SmAl3(PO4)2(OH)6. Samarium in florencite-(Sm) is substituted by other rare earth elements, mostly neodymium. It does not form separate crystals, but is found as zones in florencite-(Ce), which is cerium-dominant member of the plumbogummite group. Florencite-(Sm) is also a samarium-analogue of florencite-(La) (lanthanum-dominant) and waylandite (bismuth-dominant), both being aluminium-rich minerals.