Mineralpedia Details for Autunite
Named for the type locality near Autun at Saint-Synphorien-de-Marmagne in Burgundy, France. Autunite is an uncommon secondary mineral that results from uranium-bearing minerals in oxidizing conditions and in hydrothermal veins and granite pegmatites, and other geologic settings. It is a widespread mineral that can be found as excellent specimens in France, Portugal, Italy, Germany, England, the United States, Brazil, and Australia, among several other localities. Autunite is highly radioactive and will fluoresce a yellow-green under ultraviolet light. It will also dehydrate upon exposure to air.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/autunite.pdf
- Crystal System
- Crystal Habit
- Tabular, Micaceous, Foliated
- Perfect, Poor, Poor
- Vitreous - Pearly
- yellow, pale yellow, lemon yellow, greenish yellow, pale green
- pale yellow
- Tetragonal - Ditetragonal Dipyramidal
- View Autunite
- View Autunite
Autunite from Day Break Mine, Mt. Spokane, Cleveland Co., Washinton, United States
Nice piece from this classic and premier locality featuring naturally fluorescent greenish yellow, thin platy Autunite blades to 2cm.
Vibrant yellow-green square-tabular crystals to 9mm.
Platy, yellow-green Autunite crystals to 2cm.
Autunite from Ranger Mine, Northern Territory, Australia
Yellow, slightly green tabular, platy crystal aggregated to 4mm.
Autunite from Apex mine, Lander Co., Nevada, United States
Crystals to 3mm.
Autunite from Saint-Symphorien, near Autun, Saône-et-Loire, Burgundy, France
Superb, well-preserved specimen The crystals are bright yellow to 5mm.