Seattleguy Posted September 28, 2009 Share Posted September 28, 2009 I purchased this turtle with the hopes that itd be a good project for me to build prep skills... or gain some to begin with. I am a total newbie to this, and lack equipment. I am wondering if there is a way to remove the concretion covering the fine detail on this turtle shell with materials/ equipment that can be purchased from the local hardware store? The turtle is from the Oligocene, out of the white ash in WY. The bottom shell is present and also covered in the same thin layer of cocretion so that only the outline of the plates are visable with no fine detail. All tips welcome. Chris Link to comment Share on other sites More sharing options...
Phoenixflood Posted September 28, 2009 Share Posted September 28, 2009 I am not sure, but welcome Most of what I find washes up at my feet so I've never been faced with that issue, maybe one day though I know that there are some members here that have dealt with that formation. Hopefully someone will be able to help you The soul of a Fossil Hunter is one that is seeking, always. Link to comment Share on other sites More sharing options...
tracer Posted September 28, 2009 Share Posted September 28, 2009 ok, i'll post at the risk of sounding ignorant. i can't see perfectly from the photo, but it looks like the shell is all chalk. if so, that would mean that the dark area is really more of a stain than anything else, and that there are not two "layers" of different hardnesses, where one could be removed leaving the other one looking nice. but even if there were, in many cases the "cleaned" area would look different from the rest of the fossil. the effect i believe i'm seeing is common when part of a fossil is exposed to the sunlight and bleaches out and the rest of the fossil doesn't. if i'm correct from looking at that picture, then i wouldn't try to remove anything from the fossil if it were mine. i might consider trying to lighten the stained area a bit chemically, but i probably would just leave the thing alone. oh, i guess you could take a stiff nylon-bristled brush and some soapy water and try to scrub a bit on the darkened area and see what happens, but be careful if you do anything like that. on any fossil, i tend to think about what i want to do for a while before i try it, and then work on a tiny area first where it won't show too much if i decide to abandon the effort as unworkable. Link to comment Share on other sites More sharing options...
ozzyrules244 Posted September 28, 2009 Share Posted September 28, 2009 ok, i'll post at the risk of sounding ignorant. i can't see perfectly from the photo, but it looks like the shell is all chalk. if so, that would mean that the dark area is really more of a stain than anything else, and that there are not two "layers" of different hardnesses, where one could be removed leaving the other one looking nice. but even if there were, in many cases the "cleaned" area would look different from the rest of the fossil. the effect i believe i'm seeing is common when part of a fossil is exposed to the sunlight and bleaches out and the rest of the fossil doesn't. if i'm correct from looking at that picture, then i wouldn't try to remove anything from the fossil if it were mine. i might consider trying to lighten the stained area a bit chemically, but i probably would just leave the thing alone. oh, i guess you could take a stiff nylon-bristled brush and some soapy water and try to scrub a bit on the darkened area and see what happens, but be careful if you do anything like that. on any fossil, i tend to think about what i want to do for a while before i try it, and then work on a tiny area first where it won't show too much if i decide to abandon the effort as unworkable. I have found that plain white vinegar works well on removing matrix on most of the fossils I find as long as the matrix being removed is limestone but you have to be real careful i would try a small spot with a cotton swab first to see what happens plain water will stop the reaction if needed. "Not everything that counts can be counted, and not everything that can be counted counts." Albert Einstein Link to comment Share on other sites More sharing options...
Seattleguy Posted September 28, 2009 Author Share Posted September 28, 2009 Hey guys. Thanks for the input. Im hoping it isnt chalk. Now Im realizing that the pic I posted wasnt the best I shouldve posted (Photography is also a skill I need to improve). This is a portion of the shell that the origianl seller cleaned prior to selling, so I think something more can be done with whats left of the turtle... though Im not sure how much. The cleaned part has some good detail, you can see the small bone sutures between the shell plates.. etc. The discoloration that was noticed is I think caused by a glue or fixative that the seller used. The matrix that surrounded the turtle is a tanish/ light brown, even though the conretion on the turtle seems white. On the cleaned portion I can see what looks like very small abrasive scratches... leading me to believe the seller used... an abrasive stiff brush? an abrasive paper? - or is that silly? I definately will give vinegar a try. Any more ideas would be awesome Thanks Chris Link to comment Share on other sites More sharing options...
Seattleguy Posted September 28, 2009 Author Share Posted September 28, 2009 oh, Tracer I re-read you mentioned a stiff brush earlier.. Thank you. Link to comment Share on other sites More sharing options...
ebrocklds Posted September 28, 2009 Share Posted September 28, 2009 i use an air abrasive system to clean my white river material. i have done several turtles like yours and the best way is always to blast it off with dolomite. but that required spending a bunch of money to buy a micro-abrasive machine. ( $500 minimum) if you are a handy person and have a little spare time you can build your own for less. here is a link to the schemetics to build one. you will need an air compressor or some type of compressed air. http://www.thefossilforum.com/index.php?showtopic=294&st=-20&p=6&hl=air%20abrasive&fromsearch=1entry1942 scroll down to find the picture. Brock Link to comment Share on other sites More sharing options...
tracer Posted September 28, 2009 Share Posted September 28, 2009 i didn't mention air abrasion based on the do-it-yourself-cheap premise, but that would clearly be the best thing to try if available. the "chalk" reference was meant more broadly to refer to limestone, not soft store chalk... Link to comment Share on other sites More sharing options...
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