Trilobite Prep. Help

[fogo26]

Hey all! I was looking for a bit of advice on the best way for me to clean up this Eldredgeops rana that I found in Paulding, Ohio just yesterday. Had to knock it out of a larger chunk of shale and luckily it came out clean. It is an inch across both ways. The only issue is there is still some shale in between the thorax segments, on the eyes and glabella, and covering what I am hoping to be a squished pygidium (fingers crossed). I have got some dental picks that I have used before but that's all I have as I can't afford any blasters of air scribes.

 

I am just a bit nervous about using the picks on this piece as I do not want to damage it or scratch the fossil itself.

 

Would soaking in vinegar help at all? 

 

 

Regards,

 

Connor

[Kane]

I wouldn't go the vinegar route. I think what you are doing is fine... Patience and good control with the sharp tools is the way to go if you aren't able to invest in an air abrader at this time. You won't likely get it to 100% matrix free, but it is still possible to make a significant difference in appearance with time. If you have some means to get it under magnification while you do it, that might assist in seeing what you are doing more precisely.

[Mark Kmiecik]

Pin vice and carbide needles online for cheap. No acids. No bases. Just slow and careful picking is the way to go. Whatever the prep job is the fastest method will usually produce the worst result because the fast easy methods cannot something as small as a pinpoint and therefore abrade the specimen more than necessary. If it's a common specimen not well preserved go for fast and easy. If it's something you want to keep for your collection take the time to do it right. I've prepped 7 or so Green River fish from 4" to 10" with a pin and so I know how tedious it can be. But you can't beat the results and the satisfaction of a job done to the best possible outcome. 

[Ptychodus04]

You can also go after it with a stiff brush if the trilobite isn’t fragile. I’ve used a grout brush with good results prior to buying an abrasive setup.

[FossilDAWG]

Note that "stiff brush" does not mean wire brush.  Steel or even brass brushes will scratch the calcite shell of the trilobite, and abrade off fine detail.  A stiff nylon brush should be OK.

 

Don

[Mark Kmiecik]

A stiff hog bristle brush and some bicarbonate of soda (wet brushing) should get the matrix out of the hard to get to areas.

[Ptychodus04]

On 5/9/2019 at 6:27 PM, FossilDAWG said:

Note that "stiff brush" does not mean wire brush.  Steel or even brass brushes will scratch the calcite shell of the trilobite, and abrade off fine detail.  A stiff nylon brush should be OK.

 

Don

Agreed. The grout brush I used had stiff plastic bristles. 

 

I’ve even thrown small fossils in an ultrasonic cleaner with mixed results. The really stable ones come out beautiful but anything with cracked shell held together with matrix doesn’t fare so well.