Shuo Wang Posted April 4, 2018 Share Posted April 4, 2018 Why are trilobites brown from Russia and black from other countries? What's the difference of the mineral composition between a brown trilobite and a black one? Both the trilobite fossil and the matrix are stones, why are their colors so different? Link to comment Share on other sites More sharing options...
Fossildude19 Posted April 4, 2018 Share Posted April 4, 2018 It is dependent on the minerals that were present in the sediments and water during the fossilization process. There are many brown trilobites from the US and Canada. I've found black, white, grey, and brown trilobites in the Middle Devonian of New York State. I'm sure @doushantuo probably has some taphonomic papers that address this question. 1 Tim - VETERAN SHALE SPLITTER VFOTM --- APRIL - 2015 IPFOTM -- MAY - 2024 _________________________________________________________________________________ "In every walk with nature one receives far more than he seeks." John Muir ~ ~ ~ ~ ><))))( *> About Me Link to comment Share on other sites More sharing options...
Raggedy Man Posted April 4, 2018 Share Posted April 4, 2018 The chemical make up of the sediments contribute to the fossil. If iron is present it may give the rock a reddish color. Phosphates may darken the rock to gray or black. The trilobites I find in the Upper Mississippi Valley also have the brownish caramel color as well. As Tim stated, they're not endemic to just Russia. For example These cephalons and bits are the brownish caramel color in question. They're from Indiana The Waldron shale and are silurian. ...I'm back. Link to comment Share on other sites More sharing options...
Shuo Wang Posted April 4, 2018 Author Share Posted April 4, 2018 41 minutes ago, Fossildude19 said: It is dependent on the minerals that were present in the sediments and water during the fossilization process. There are many brown trilobites from the US and Canada. I've found black, white, grey, and brown trilobites in the Middle Devonian of New York State. I'm sure @doushantuo probably has some taphonomic papers that address this question. Thanks for your explanation. Link to comment Share on other sites More sharing options...
Shuo Wang Posted April 4, 2018 Author Share Posted April 4, 2018 21 minutes ago, Raggedy Man said: The chemical make up of the sediments contribute to the fossil. If iron is present it may give the rock a reddish color. Phosphates may darken the rock to gray or black. The trilobites I find in the Upper Mississippi Valley also have the brownish caramel color as well. As Tim stated, they're not endemic to just Russia. It turns out that iron is the "brownish ingredient". Thanks a lot for your answer! Link to comment Share on other sites More sharing options...
Shuo Wang Posted April 4, 2018 Author Share Posted April 4, 2018 1 hour ago, Raggedy Man said: The chemical make up of the sediments contribute to the fossil. If iron is present it may give the rock a reddish color. Phosphates may darken the rock to gray or black. The trilobites I find in the Upper Mississippi Valley also have the brownish caramel color as well. As Tim stated, they're not endemic to just Russia. For example These cephalons and bits are the brownish caramel color in question. They're from Indiana The Waldron shale and are silurian. If iron was present during the fossilization process, why is only trilobite brown? It looks like brownish trilobites are usually with white or gray matrix stones. Link to comment Share on other sites More sharing options...
Kane Posted April 4, 2018 Share Posted April 4, 2018 This bumps up against the question of biochromes (organic pigments) and sclerochromes (colours associated with structure). It sounds like a trip to the library may be in your future! 1 ...How to Philosophize with a Hammer Link to comment Share on other sites More sharing options...
Shuo Wang Posted April 4, 2018 Author Share Posted April 4, 2018 1 hour ago, Kane said: This bumps up against the question of biochromes (organic pigments) and sclerochromes (colours associated with structure). It sounds like a trip to the library may be in your future! It seems to be a complicated issue. Link to comment Share on other sites More sharing options...
ynot Posted April 4, 2018 Share Posted April 4, 2018 There are other elements that can cause black or brown colors besides iron. You can also have combinations of trace elements that will affect the color of a fossil. It is a very complex subject. 1 Link to comment Share on other sites More sharing options...
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