Alexander D.G Posted November 23, 2018 Share Posted November 23, 2018 Good day everyone, The pictures below show from what i know an ammonite fossil imprint, but what is it? How can it be that it is such deep blue color? As shown in the second picture the fossil is about 1 cm long, it was found in Aguas de Madeiros, Portugal. Any insight would be greatly appriciated! 1 Link to comment Share on other sites More sharing options...
ynot Posted November 23, 2018 Share Posted November 23, 2018 The color is caused by the mineral(s) present during fossilization. Possibly copper minerals (azurite). 2 Darwin said: " Man sprang from monkeys." Will Rogers said: " Some of them didn't spring far enough." My Fossil collection - My Mineral collection My favorite thread on TFF. Link to comment Share on other sites More sharing options...
Alexander D.G Posted November 23, 2018 Author Share Posted November 23, 2018 It does seem te be the same color as azurite, thanks was wondering about this one for a while now! Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted November 23, 2018 Share Posted November 23, 2018 The fossils are found in a 'blue marl' / marlstone. The blue colour is caused by the oxidation of sulphide minerals to become acidic sulphates which can exhibit a blue colour especially when the original mineral was pyrite. 6 Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
Alexander D.G Posted November 23, 2018 Author Share Posted November 23, 2018 I found a couple of pyrite chuncks near the fossil so it is possible that the Original mineral was pyrite. 2 Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted November 23, 2018 Share Posted November 23, 2018 I expect so. I do not know your locality, but I do know this is the case in the 'blue marls' of South West England. Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
Ludwigia Posted November 23, 2018 Share Posted November 23, 2018 It may help with the id if you could find out what the precise statigraphy is. I'm thinking Harpoceras, but that's a shot in the dark. Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted November 23, 2018 Share Posted November 23, 2018 2 minutes ago, Ludwigia said: It may help with the id if you could find out what the statigraphy is. I believe it's probably the Agua de Medeiros Formation which is Upper Sinemurian. (probably!) Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
Ludwigia Posted November 24, 2018 Share Posted November 24, 2018 10 hours ago, Tidgy's Dad said: I believe it's probably the Agua de Medeiros Formation which is Upper Sinemurian. (probably!) Well, that would rule out Harpoceras then. That leaves one of any number of ammonites to choose from. I'm afraid that the preservation is not good enough to show up any distinguishing features clearly enough for me to hazard a guess. 1 Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
Alexander D.G Posted November 24, 2018 Author Share Posted November 24, 2018 I am not familiar anough with the dating of fossils to make a guess but this might help you guys. The other kinds fossils i found along side this specimen were an enormous amount of Gryphaea, a pyritised ammonite and some bivalve. Link to comment Share on other sites More sharing options...
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