Getting Moss Off of Chalk Fossils

[Heteromorph]

I have a Tridenticeras peramplum ammonite steinkern from the Austin Chalk that has part of it incrusted with algae/moss from sitting in a small creek where I found it. What would be recommended to clean moss off of chalk fossils, not just ammonites? What ever the method that is recommended I would first try it out on a fossil-less chunk of chalk to make sure that the process wouldn’t be detrimental to the matrix. I also don’t want to scratch the fossil by scrubbing it with something overly abrasive since the matrix weakens when wet. I usually use a soft bristled toothbrush for cleaning dirt off of specimens. Would that enough? 

 

Thanks in advance!

[-AnThOnY-]

Sometimes, if its thick enough, once its dry you can just use your finger nail to scratch it off and it will separate cleanly. 

 

Other times, it could be like a stain, which unfortunately I haven't figured out how to remedy without getting it wet or using abrasives (which I don't have)

[Tidgy's Dad]

I haven't done this in many, many years, but i used to use a toothbrush with some success. 

[Ptychodus04]

1 cup of bleach in 1 gallon of water. Brush it onto the moss/algae and it will kill it. Then give it a good scrub with a hard bristle brush.

[Heteromorph]

34 minutes ago, Tidgy's Dad said:

Sometimes, if its thick enough, once its dry you can just use your finger nail to scratch it off and it will separate cleanly. 

 

Other times, it could be like a stain, which unfortunately I haven't figured out how to remedy without getting it wet or using abrasives (which I don't have)

 

34 minutes ago, Tidgy's Dad said:

 

I haven't done this in many, many years, but i used to use a toothbrush with some success. 

 

 

13 minutes ago, Ptychodus04 said:

1 cup of bleach in 1 gallon of water. Brush it onto the moss/algae and it will kill it. Then give it a good scrub with a hard bristle brush.

Thank you!

[JohnJ]

To keep from saturating your specimen too much, you can lay tissue paper on specific areas and saturate the paper with the bleach solution.

[Ptychodus04]

1 hour ago, JohnJ said:

To keep from saturating your specimen too much, you can lay tissue paper on specific areas and saturate the paper with the bleach solution.

 

The Austin chalk is typically very resistant to damage (at least it is here in the DFW area). Soaking it should not soften it enough to make a real difference unless the ammonite is severely weathered.