Fossil Cleaning

[rod]

This may be a stupid question, but I am new to fossils and dont want to mess them up.

while searching a lime quarry in North Mississippi, We found these shells. How do I go about removing the lime / limestone from them?

[Fossildude19]

Hello Rod,

First, try soaking them in soap and warm water.

Then, if that's not cutting it, you can try soaking them in plain white vinegar.( I would try on one specimen first, and see how that works out. )

If that still isn't making a dent, you could try diluted muriatic acid - But,... use this with caution and in a well ventilated area!

Sometimes, you can also just chip the matrix off with a small dental pick, or wire brush. Try this on poor quality fossils, though, to see what it will do. You do not want to be testing on your best specimens.

Another thing you can try is air abrasives. This can be a bit more involved and pricey, but West4me just posted a neat HOW TO for a portable cabinet that you should check out.

http://www.thefossilforum.com/index.php?showtopic=14043

By the way there are no such things as stupid questions,...- we are all here to learn.

Hope this helps a little.

Regards,

Edited June 29, 2010 by Fossildude19

[Harry Pristis]

This may be a stupid question, but I am new to fossils and dont want to mess them up.

while searching a lime quarry in North Mississippi, We found these shells. How do I go about removing the lime / limestone from them?

If the fossils are harder than the matrix, try a Dremel rotary tool with a stainless steel wire brush. Try it on a practice fossil until you get the knack.

[tracer]

first thing i would do would be to brush them with a nylon-bristled brush in water. that would probably make them acceptable to go into my collection. if it did not, i might try a vinegar solution for a while, since the shell material looks original and should be a bit more resistant than the matrix. but bear in mind, if both the matrix and the shell material are calcium carbonate, you'll be etching/dissolving both at once to a degree. you also need to fully neutralize the reaction if you stop it. it's kind of good to pick up an ugly specimen or two to practice on if you're not sure...

[Terry Dactyll]

Rod..... I cant really add to whats already been said, but nice finds and let us know how you get on.....

[rod]

first thing i would do would be to brush them with a nylon-bristled brush in water. that would probably make them acceptable to go into my collection. if it did not, i might try a vinegar solution for a while, since the shell material looks original and should be a bit more resistant than the matrix. but bear in mind, if both the matrix and the shell material are calcium carbonate, you'll be etching/dissolving both at once to a degree. you also need to fully neutralize the reaction if you stop it. it's kind of good to pick up an ugly specimen or two to practice on if you're not sure...

Thanks for the info. We decided to wash them off and keep them natural. The limestone that is left is mainly around where the top and bottom join, so it is not in a position of distracting form the shells.

[jhw]

They really don't look bad the way they are. But if it was me I'd probably pick and scrape at 'em a little. As mentioned, some kind if dental pick works well. I'm not a purist, so personally I like my shells to look pretty and that includes minor smoothing if needed. Wet/dry sand papers a staple and I usually coat the finished product with a spray finish, just to kind of seal them and bring out the color. I like the Krylon Chrystal Clear in a matte finish.