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GeneralPortugal Geological Museum in Lisbon

25th Oct 2022 14:43 UTCBill Hamel 🌟

Just finished a quick trip through Portugal & got a chance to tour the Portugal Geological Museum in Lisbon (Museu Geologico de Portugal). A fabulous museum full of Paleontological Treasures. Numerous fossils & geological displays from Portugal & a small, well displayed mineral collection. Well worth the visit if you are in Lisbon. Just fabulous!

25th Oct 2022 14:44 UTCBill Hamel 🌟

And the largest tubular pyrite conception I have ever seen. Note the fire extinguisher for a size reference.

25th Nov 2022 10:56 UTCRui Nunes 🌟 Expert

Not a pyrite concretion

"The Pedra Furada is an outcrop showing hundreds of ferruginised sandy tubes. The tubes are considered to represent vertical escape channels for overpressured water. The ferruginisation is due to iron oxides associated with colloidal/clayey fine sediments and to goethite formed from solution.

Quartz, feldspars (orthoclase and microcline), mica and kaolinite, were the main silicate minerals identified by X-ray diffraction in the three bands of the tubes (inner, intermediate and outer bands). Goethite was the only iron oxide mineral identified.
In: T.M. Azevêdo, M.M. Abreu, M. Azevedo Coutinho, J. Figueiras - The origin of the Pedra Furada sandstone tubular structures (South of Lisbon, Portugal), 2006."

25th Oct 2022 20:51 UTCRui Nunes 🌟 Expert

Museu Geológico de Lisboa https://www.mindat.org/museum-338.html

25th Nov 2022 12:59 UTCBill Hamel 🌟

Thanks for the information/clarification. A very interesting structure! Thanks - Bill

25th Oct 2022 21:41 UTCEddy Vervloet Manager

https://www.mindat.org/a/geological_museum_of_lisbon