Sealing cracks in matrix?

[strochim]

I'm looking for suggestions and recommendations on how to repair this fossil I just found. It's got 4 crabs and an insect on the matrix, but it is cracking on top in several places, and it will fall apart easy if I'm not extremely careful. What is the best way to seal these cracks? Glue? What kind?

Thanks in advance for help.

 

[FranzBernhard]

For essentially non-porous and non-crumbly rocks, you can put a small drop of thin superglue in obvious cracks. Its non-professional, but fast, easy and cheap and its also somewhat reversible.

Franz Bernhard

[Ludwigia]

I can't judge whether or not fossils are in this piece, but you could take up Franz's suggestion and trickle some highly fluid superglue into the cracks and press them firmly together. Difficulties may however arise if there are loose matrix crumbs within the cracks which would hinder a snug fit. If that's the case, you would need to take the block apart at the cracks and clean off the inner surfaces before glueing them back together.

[oilshale]

I can't see any fossils in the pictures so I can't say anything about it, but the rock looks a lot like limonite (or some other Iron compound) to me. How did the cracks form? Were they there before the salvage? Does the rock perhaps contain pyrite? If so, the cracks could have been caused by pyrite decay. In that case, Elmer's glue would be exactly the wrong glue - it would make the whole thing even worse. Elmer's glue is ok for simple bonding but it contains water and can accelerate pyrite rot. Low viscosity superglue is the right one for such a case.

 

Edited January 14, 2022 by oilshale

[jpc]

The advice above is good, but in your other post, I think it is clear that there are no fossils here.  keep on looking, though.