alunite
/ˈæljʊnaɪt/Definitions
1. noun
A secondary mineral species of aluminium phosphate, typically a colorless or white triclinic mineral.
“The geologist studied the formation of alunite in the ancient volcanic region.”
2. noun
A type of sulfate mineral, hydrated aluminium sulfate, often found in caves and hot springs.
“The speleologist discovered a beautiful formation of alunite in the underground cave system.”