Alunite from Mt. Diablo, NV, USA – miniature specimen as unique piece
This miniature specimen displays a compact aggregate of Alunite with a waxy luster and pastel hues of cream, pink, and pale green. The material is slightly translucent with a conchoidal fracture, and subtle color transitions are enhanced by associated clay minerals, highlighting its secondary origin.
Alunite is a potassium- and aluminum-rich sulfate mineral typically formed under hydrothermal conditions in acidic volcanic rocks. It develops through advanced hydrothermal alteration and is of both economic and petrological interest. The finest specimens are known from well-documented sites such as Mt. Diabolo.
Geology & Origin:
Mt. Diablo in Nevada is part of an extensively altered volcanic system with a history of active hydrothermal processes. Alunite occurs there as a characteristic product of advanced alteration in rhyolite and other acidic rocks. The locality is considered a classic example of alunitic zone formation and is frequently referenced in ore deposit research.