JohnBrewer Posted April 26, 2016 Share Posted April 26, 2016 Hello forum members Do different stromatolites have classifications/individual Latin names? I can't seem to find much on the web. I've been given these stromatolites which came from Morocco and I'd like to label them. Thanks John John Map of UK fossil sites Link to comment Share on other sites More sharing options...
DPS Ammonite Posted April 26, 2016 Share Posted April 26, 2016 I have never seen stromatolites in the shape of polygons. Could they be chalcedony filling spaces formally occupied by another mineral such as calcite. Search Google images for "polygonal agates" and "polyhedroid agates". My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
Fossildude19 Posted April 26, 2016 Share Posted April 26, 2016 These actually look more like differentially weathered, cut to shape (or broken) Liesegang banding than stromatolites, ... to me. Regards, Tim - VETERAN SHALE SPLITTER VFOTM --- APRIL - 2015 __________________________________________________ "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...
DPS Ammonite Posted April 26, 2016 Share Posted April 26, 2016 John, Send some photos of the edges. Do you think that the edges have been cut? What do you think that the rocks are made of chalcedony, carbonate etc. My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
Carl Posted April 26, 2016 Share Posted April 26, 2016 I'm with my man, Tim. Not stromatolites, but some kind of Liesegang structure. That triangular receptacle is SUPERB! Link to comment Share on other sites More sharing options...
JohnBrewer Posted April 26, 2016 Author Share Posted April 26, 2016 Thanks guys, I'll take more photo when I return from the bar where I'm supping some lovely local ale The certainly have bases and sides which are natural and not cut. Pretty weird things eh? J John Map of UK fossil sites Link to comment Share on other sites More sharing options...
Ridgehiker Posted April 26, 2016 Share Posted April 26, 2016 Yes weird but good weird. In general stromatolites are difficult to identify as 'stromatolites'. I have had three older Doctor emeritus paleontologists...160 years experience among them... come to no consensus with a specimen I have found. This included looking at thin sections under a microscope. The internal structure often silicifies and the layers can be indistinguishable from non organic forms. Link to comment Share on other sites More sharing options...
JohnBrewer Posted April 26, 2016 Author Share Posted April 26, 2016 Hi folks More pictures from underneath and sides. John Map of UK fossil sites Link to comment Share on other sites More sharing options...
JohnBrewer Posted April 26, 2016 Author Share Posted April 26, 2016 John Map of UK fossil sites Link to comment Share on other sites More sharing options...
abyssunder Posted April 26, 2016 Share Posted April 26, 2016 Excellent! I agree with Tim (very good visual memory)! http://www.thefossilforum.com/index.php?/topic/37514-mysterious-skull-that-i-found-in-oregon/ " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
JohnBrewer Posted April 26, 2016 Author Share Posted April 26, 2016 Thanks guys. I must say they're really beautiful and tactile. John Map of UK fossil sites Link to comment Share on other sites More sharing options...
DPS Ammonite Posted April 27, 2016 Share Posted April 27, 2016 The side views confirm that these are not agates and not stromatolites. They are sandstone with Liesegang banding and rings. My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
fifbrindacier Posted April 27, 2016 Share Posted April 27, 2016 Weird finds, yes, but nice ones, you're a lucky guy ! "On ne voit bien que par le coeur, l'essentiel est invisible pour les yeux." (Antoine de Saint-Exupéry) "We only well see with the heart, the essential is invisible for the eyes." In memory of Doren Link to comment Share on other sites More sharing options...
JohnBrewer Posted April 27, 2016 Author Share Posted April 27, 2016 The side views confirm that these are not agates and not stromatolites. They are sandstone with Liesegang banding and rings. Isn't sandstone soft though? These are really hard in every part. John Map of UK fossil sites Link to comment Share on other sites More sharing options...
DPS Ammonite Posted April 27, 2016 Share Posted April 27, 2016 John, Sandstone can be tough; it depends mainly on the cement. Do you see something other than sandstone in these rocks? Is there chalcedony in the layers? I can't tell for sure by your photos. Sometimes a rock in the hand is worth a thousand pictures and thus a million words. My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
JohnBrewer Posted April 27, 2016 Author Share Posted April 27, 2016 I'm not sure of my rock types so I can't say chalcedony as I don't know what that is! I'll need to have a Google. All of the rock parts are really hard hence the sandstone question. Maybe you or someone else could recommend a book/PDF so I can lean about identifying different rock types? John Map of UK fossil sites Link to comment Share on other sites More sharing options...
DPS Ammonite Posted April 27, 2016 Share Posted April 27, 2016 Chalcedony usually has a waxy luster and is a type of microcrystalline quartz similar to agate. Do all the layers look like sand or silt sized particles? Scratch with a steel knife layers that are not silt or sand. Steel will not scratch chalcedony. My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
DPS Ammonite Posted April 29, 2016 Share Posted April 29, 2016 I'm not sure of my rock types so I can't say chalcedony as I don't know what that is! I'll need to have a Google. All of the rock parts are really hard hence the sandstone question. Maybe you or someone else could recommend a book/PDF so I can lean about identifying different rock types? Check out this site: https://www.uwgb.edu/dutchs/Petrology/IdentifyRxMin.htm My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
JohnBrewer Posted April 29, 2016 Author Share Posted April 29, 2016 Thanks DPS looks just what I need. Interesting I went and saw a professional geologist today who also sells a few fossils as well as minerals &c, and took a chunk along. He's been a geologist for 40 years or so and has never seen anything like this and he travels the world for geological specimens. He did say if it's geological he couldn't work out how it formed. I've left a piece with him as he has a Moroccan rep coming to him soon so will ask him. One of his staff members did a quick Google 'Precambrian Moroccan stromatolite' and there's a stack of the same things on eBay but no information so like many things on auction sites they're probably misidentified. John Map of UK fossil sites Link to comment Share on other sites More sharing options...
JohnBrewer Posted April 29, 2016 Author Share Posted April 29, 2016 Chalcedony usually has a waxy luster and is a type of microcrystalline quartz similar to agate. Do all the layers look like sand or silt sized particles? Scratch with a steel knife layers that are not silt or sand. Steel will not scratch chalcedony. The outside sides do feel sort of waxy and have the same look as wax i.e. Not mat or glossy but a low sheen. Haven't tried the steel scratch test and I gave the least aesthetically pleasing on the the geologist! John Map of UK fossil sites Link to comment Share on other sites More sharing options...
abyssunder Posted April 29, 2016 Share Posted April 29, 2016 In a closer view of the picture I've posted, there are visible cracks between the "elements". I think it's easy to split along the cracks to obtain the forms in question. The outer surfaces of them near the cracks are probably recrystallized, or the cracks are infilled with crystals so they could be harder than the inner parts. " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
JohnBrewer Posted April 30, 2016 Author Share Posted April 30, 2016 Thanks Abyssunder. When I get some time next week I think I'll run one through the tile saw. John Map of UK fossil sites Link to comment Share on other sites More sharing options...
JohnBrewer Posted May 5, 2016 Author Share Posted May 5, 2016 Want one? http://www.thefossilforum.com/index.php?/topic/64877-my-turn-to-payback/?p=678558 John Map of UK fossil sites Link to comment Share on other sites More sharing options...
doushantuo Posted May 5, 2016 Share Posted May 5, 2016 I've seen stuff like that in ECONOMIC GEOLOGY,but can't for the life of me remember the geochemical background. Three-phase sulfide colloidal preciptation? self organized reaction diffusion front? Link to comment Share on other sites More sharing options...
JohnBrewer Posted May 12, 2016 Author Share Posted May 12, 2016 Bump for the auction! Finishes in 4 hours. Grab yourself an intriguing, beautiful and tactile triangular sandstone rock with Leisegang banding for a few $$ and help the forum. Strangely it doesn't seen to feel cold to the touch. It's not fragile and would make a great paperweight, ornament or addition to your collection. The waxy feel is rather sexy.... FREE WORLDWIDE SHIPPING! John Map of UK fossil sites Link to comment Share on other sites More sharing options...
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