07 – Fluorita de Iraí
Ano 02 (2015) - Número único Artigos
Herbert Pöllmann, Institut für Geowissenchaften, Universität Halle, Alemanha
| Calcite | Gypsum | Baryte |
| Agate | Quartz | Karneol |
| Chalcedony | Lepidokrokite | Pseudomorphosis of quartz after anhydrite |
| Pseudomorphoses of quartz after calcite | Goethite | Fluorite |
Fluorite can only sometimes be found in these geodes, mainly in spherical arrangements grown on amethyst. A summary on these fluorites is published in journal Aufschluss in 2010 (Pöllmann, 2010).
Figure 1. Amethyst geode with spherical aggregates of fluorite and SEM image showing a very nice sphere made of cubic crystals of this mineral. (Ø = 2cm in image on the right).
REFERENCES
PÖLLMANN, H.: Kugelfluorit auf Amethyst aus Rio Grande do Sul/Brasilien. Der Aufschluss, Jg. 61 Heidelberg, 321-323, (2010).