Preparing bivalves and gastropods in loose matrix?

[ElToro]

I have dug a number of bivalves and gastropods out of a very friable, crumbly matrix. Anyone have any experience how I can preserve some of the matrix and also make the specimens look good?

[izak_]

What type of rock is it?

[ElToro]

Ranging from super crumbly sandstone to very hard limestone. Some are very cemented and need no work except a little clean, but the sandstone ones are different. I have a nice slab of sediment with bivalves and a gastropod in it but its fragile. Every time I pick it up a little more crumbles off.

[ElToro]

Here it is. Really cool with many fossils.

[ElToro]

Of course I want to clean around the fossils to make them pop but don't know what I can do about the matrix

[Ptychodus04]

Set the whole thing in a box of sand to support the entire specimen evenly. Then do your prep work. This should minimize the breakage. Once you have the prep to your liking, apply some very thin consolidant (PVA or Butvar). This will penetrate deep into the matrix to hold it together. Be sure not to touch the matrix when it is wet with the solvent or you will tear it apart. After 2-3 applications of the consolidant (and it has had plenty of time to dry), flip the specimen over in the sandbox and apply the same procedure to the reverse.

This process should stabilize the matrix well with minimal opportunities for damage.

[ElToro]

Set the whole thing in a box of sand to support the entire specimen evenly. Then do your prep work. This should minimize the breakage. Once you have the prep to your liking, apply some very thin consolidant (PVA or Butvar). This will penetrate deep into the matrix to hold it together. Be sure not to touch the matrix when it is wet with the solvent or you will tear it apart. After 2-3 applications of the consolidant (and it has had plenty of time to dry), flip the specimen over in the sandbox and apply the same procedure to the reverse.

This process should stabilize the matrix well with minimal opportunities for damage.

Thanx mate! That's exactly the info I need. And there's plenty of sand here in Perth.

I'll go to hardware store on the weekend.

[Twinlukers]

Very helpful!!!! I was wondering the same.

Most of my finds are in limestone. But some of my ammonites

Are in a clay deposit. Do I do the same?

I'm using a drumel to shave around the metrics. But staying clear of the piece.

[ElToro]

Very helpful!!!! I was wondering the same.

Most of my finds are in limestone. But some of my ammonites

Are in a clay deposit. Do I do the same?

I'm using a drumel to shave around the metrics. But staying clear of the piece.

Yea some of mine are in brutally hard limestone. Havnt even tried to prep!

[Ptychodus04]

Very helpful!!!! I was wondering the same.

Most of my finds are in limestone. But some of my ammonites

Are in a clay deposit. Do I do the same?

I'm using a drumel to shave around the metrics. But staying clear of the piece.

If you want to keep the ammonites in the matrix then you can use the same process.