Getting the Fossil Prep Right, not overdone. Looking for Advice.

[RedDevl]

Hello everyone,

A geologist friend of mine roped me into his love of all things ancient, so here I am new to the fossils, and new to the Fossil Forum.

 

I received my first Green River fish slab yesterday and spent most of the day on and off working off the layers with dental scaler that I've used for in the past for Roman coins.  Must say that this matrix is much easier than the stuff encrusted to the coins!

 

So far I'm pretty happy with the progress, but am looking for advice on how far to take this so that I don't overwork the piece.  Here are a couple of photos of the progress.  Note the series of three stages use lighting from the top to highlight the 3D effect of the specimen.  The other photo uses light from the lower left to show a more natural visual look if you just look at it laying on the table.

 

I believe I still have a lot of detail work taking off sediment between the bones and along the spine, etc.  Any advice on around the head and eye socket, the border?   How about surface finishing?  If the slab is dampened, the fish stands out more, so would a mat clear coat of something be a reasonable finish, or should I leave it alone?  I believe I read that a 20% solution of white glue in water might create a good effect.  Any experience with that?  Again, there seem to be many schools of thought.  Thanks in advance for your help.

 

Also, I believe this is a Knightia, but wouldn't mind confirmation from someone in the know.  The fish is almost exactly 4" head to tail.  Again, thanks.

[Ptychodus04]

There appears to be some odd preservation here as my experience has always been that the bones are a uniform dark color rather than so mottled. Is this possibly tool damage? I’m not familiar with dental scalers. Or is this where matrix is still adhering? If it’s matrix, I’ve heard a gum eraser can take it off. 

 

If you have access to a micro abrasive system, that’s even better.

[Kane]

Welcome to the forum  

 

A very nice fish, indeed, and quite nicely prepped, too!

 

... I was about to tag Kris, but he just replied!

 

[Ptychodus04]

1 minute ago, Kane said:

Welcome to the forum  

 

A very nice fish, indeed, and quite nicely prepped, too!

 

... I was about to tag Kris, but he just replied!

 

 

A fortuitous cosmic coincidence... 

[snolly50]

Rest your hands. It's easy to get entranced by the prep and to inadvertently cause some real hand stress. An art gum eraser might be OK at this point, as Kris suggests; but from the photo it would seem that switching to a needle might cut through a little more matrix. It looks great and is certainly an excellent result so far. I would not use white glue. I have used clear matte acrylic spray on Green River fish. But this is a very unpopular stance due to yellowing that occurred with older formulations of acrylic. Typically Green River fish will do fine without any coating. Your mileage may vary. Good luck, most of all have fun; but be careful, it's addictive.   

[caldigger]

I'm actually seeing this as a good stopping point. Looks good. I doubt I could do anything as well.

Excellent job for a first prep and a nicely positioned fish you got.

There might be some minor cleaning to do. Hard to tell from the photos, but it would be displayable right now in my eyes.

[Sagebrush Steve]

You're doing a great job.  I agree you could keep removing matrix from between the bones and along the spine, but if you do so, I'd strongly recommend you do so under magnification.  A stereomicroscope at around 6-12 power would be best, but if that isn't practical, at least use a good magnifier, preferably one you wear on your head to keep both hands free.  You should use a probe with a sharp point--a sewing needle held in a pin vise works well.  As for coating, TFF members have all sorts of ideas about what works best.  Consensus for Green River fossils seems to be that most people don't see the need to coat them.

 

And I agree it looks like you have a Knightia eocaena.  Looks to me like it came from the 18" layer, it doesn't look like the spit fish layer.  The 18" layer produces the more desirable specimens and yours looks good.  Here's a paper that will help you confirm the identification.  Sorry for the low resolution, I had to keep the file size under the 3.95 GB limit.  You can do a google search to find the original online if you so desire, but this version should help:

 

Revision of Knightia genus1.pdf

[Ludwigia]

Everybody has given you some very good advice from their point of view, so all you need to do now is pick and choose and develop your own style. You've certainly done an excellent job up to this stage, particularly for someone with little experience. Welcome to the forum!

[RedDevl]

Thanks for all the kind words and great suggestions.  I can see that the fine detailed matrix removal takes a lot more time than first uncovering the fossil.  The areas between the ribs are a slow go with a light touch.  I'm enjoying the focus and patience and can already appreciate the amount of work that goes into a finely prepared specimen.  I think this one will look great in a shadow box with a bit of LED lighting from above to highlight the three dimensionality.  Here are a couple photos at the 7-8 hour mark and the 9-10 hour mark with the light from the 12 o'clock position.  I worked on the head and the front half of the body. I believe it is becoming noticeable as the matrix is removed from the ribs.  I'm happy with the result thus far.

[Sagebrush Steve]

53 minutes ago, RedDevl said:

Thanks for all the kind words and great suggestions.  I can see that the fine detailed matrix removal takes a lot more time than first uncovering the fossil.  The areas between the ribs are a slow go with a light touch.  I'm enjoying the focus and patience and can already appreciate the amount of work that goes into a finely prepared specimen.  I think this one will look great in a shadow box with a bit of LED lighting from above to highlight the three dimensionality.  Here are a couple photos at the 7-8 hour mark and the 9-10 hour mark with the light from the 12 o'clock position.  I worked on the head and the front half of the body. I believe it is becoming noticeable as the matrix is removed from the ribs.  I'm happy with the result thus far.

Looking great!

[RJB]

Youve done a great job.  Youve got a fish with some very hard bone and in some very nice rock.  Looks to be from the 18 inch?   If you do more fish, you will find that some bones are much softer and the rock too that will need a 'softer' touch at prepping.    its a great hobbie for sure.  Good luck on your next prep addventure.

 

RB

[RedDevl]

Being new to this I have much to learn, including what to look for to determine which layer.  From what I've read I'd assume this was from the split layer because of what I believe is a laminated sedimentation, not the 18-inch, which I understand does not exhibit lamination.  Here are a couple of photos of the edge of the shale plate.  This plate came from a well-known quarry in Kemmerer, WY if that helps.  Not sure if you can identify companies in the forum or not.

[Sagebrush Steve]

On 1/25/2018 at 4:12 PM, RedDevl said:

Being new to this I have much to learn, including what to look for to determine which layer.  From what I've read I'd assume this was from the split layer because of what I believe is a laminated sedimentation, not the 18-inch, which I understand does not exhibit lamination.  Here are a couple of photos of the edge of the shale plate.  This plate came from a well-known quarry in Kemmerer, WY if that helps.  Not sure if you can identify companies in the forum or not.

Your original “as received” photo doesn’t look like anything I’ve seen from the split fish layer.  Those fossils split in two, with some of the fish ending up on one side and the rest on the other.  Take a look at the first photo in this thread to see what they look like:

 

I don’t have as much experience with fish from the 18 inch layer but from what I’ve seen yours looks similar to those specimens.  Maybe some experts can chime in.

 

@Ptychodus04 @snolly50 @RJB

[Ptychodus04]

This matrix looks exactly like the matrix of the Phaerodus that I preppednuo for @RJB last fall. Very laminated and dark colored. Ron, what layer was that from?

 

Definitely not the Split Fish Layer.

[snolly50]

If you wish, take a tool and scratch the back of the plate paying close attention to any odor produced. If it smells like the underside of a '63 Buick Electra, it's probably 18 inch material. If not, best bet, it's from another locale. Of course, I have found the petroleum smell to be fairly noticeable; so, if present, you would probably have perceived it during your prep efforts.  

 

I am not certain the petroleum trait is always present in 18 inch stuff; but it's been there with the pieces I've handled, and not noticed in split fish prep. I have prepped split fish layer fish that were completely obscured by matrix. So, it does sometimes happen that the "split" is not at the exact fish location.

[RJB]

@Ptychodus04, that fish you did for me was from the 'bottom cap' whitch  is below the 18 inch layer.  I dont think this fish is from that layer, but maybe from the 18 inch.  Looks like purty good rock. 

 

RB

[RedDevl]

While I was working the initial hours on this I most definitely smelled petroleum, just like when passing a refinery on the highway.  My wife could smell it, too, so I wasn't imagining it.   I understand large parts of the Green River Formation is rich in shale oil so I wasn't completely surprised. 

 

The bug has bitten.  I just bought a old Nikon SMZ-2 stereo microscope due to be delivered later this week.  Once it's cleaned up I'll start working the white areas all around the fish.  The 3x Optivisor has been great, but I can see a bit more magnification helping in the detail work.  I'd better be careful or soon I'll own an air scribe and a dolomite blaster!  Going to finish this one manually, though.

[snolly50]

20 minutes ago, RedDevl said:

The bug has bitten.  I just bought a old Nikon SMZ-2 stereo microscope due to be delivered later this week. 

That's great. Prepping is addictive. The stereoscope will be a great asset. Unfortunately, as the addiction grows you will find yourself selling the Porsche and buying a pickup you can take off-road to haul out fossil finds. 

 

Since you perceived the petroleum smell, you can be pretty sure it's 18 inch layer material.

 

 

[Tidgy's Dad]

Five keys : 

 

1. Practice  (on stuff you don't mind breaking, especially)

2. Patience. 

3. Practice

4. Knowing when to stop.

5. Practice.

 

That's about it, i think. 

Oh, and practice. 

 

[Sagebrush Steve]

23 minutes ago, RedDevl said:

While I was working the initial hours on this I most definitely smelled petroleum, just like when passing a refinery on the highway.  My wife could smell it, too, so I wasn't imagining it.   I understand large parts of the Green River Formation is rich in shale oil so I wasn't completely surprised. 

 

The bug has bitten.  I just bought a old Nikon SMZ-2 stereo microscope due to be delivered later this week.  Once it's cleaned up I'll start working the white areas all around the fish.  The 3x Optivisor has been great, but I can see a bit more magnification helping in the detail work.  I'd better be careful or soon I'll own an air scribe and a dolomite blaster!  Going to finish this one manually, though.

That Nikon is a good scope, excellent choice.  Back in the days I when I designed hybrid microelectronic circuits for HP that was my go-to scope.  With it and a needle probe you shouldn’t need anything else.  And glad to see we’ve confirmed the ID as from the 18” layer, I was pretty sure that’s what it was.  Tidge has given you good advice, patience is key.  And do try to practice first on something else you don’t mind damaging to get a feel for working under the scope.  You won’t go back to the optivisor once you have used the scope!

[RJB]

@RedDevl,  Ive been thinkin about getting a scope myself.  Once you get it can you post a picture?  Thanks

 

RB

[jpc]

That looks very much like an 18 inch layer fish.  The split fish is a much yellower layer.  With browner bones.  

In addition to this list...

 

Five keys : 

 

1. Practice  (on stuff you don't mind breaking, especially)

2. Patience. 

3. Practice

4. Knowing when to stop.

5. Practice.

 

That's about it, i think. 

Oh, and practice. 

 

... I would add this one - 

6. Patience.  Do not rush. 

 

Yes, you might end up with a full prep lab. Like some of us have.  

 

 

[RedDevl]

@RJB, I'm happy to post photos of the scope when I get it.  Nothing better than a new (old) toy.

[RedDevl]

My stereo microscope was delivered this evening.  After some initial clean-up, still needs more, I assembled it and took a quick look at my fish.  WOW!  What a huge difference in my ability to see detail, literally down to the sediment grain size.  It now looks like I'm moving sand on the beach.  I took a phone photo thru the eyepiece, so you can get an idea of an 8x view.  I'll have to get an adapter for my cameras because the view is tremendous and certainly worth sharing. The scope is currently set up for 8x to 40x.  I can see I'll probably be using 8x to about 20x enlargement for most tasks.

 

I'll post some better scope pictures after I've had some more time to clean it up and take some proper photos.

[snolly50]

 

11 hours ago, RedDevl said:

My stereo microscope was delivered this evening.

Great rig! I note that your boom is set very low. When you work on fossils that are more 3-D than a fish slab, you will no doubt find it more utile to have greater relief under the scope's lens. A Barlow lens (reducing), if you do not already have one, will be a great addition to your set-up. On my vintage Bausch & Lomb Stereoscope I have affixed a 0.5X Barlow. I have found that addition very helpful.

 

Edit: I forgot to mention, as you move the unit up the boom; obviously the height of the eyepieces change. Of course that makes your seating arrangement obsolete. I ended up buying a cheap, height adjustable stool.

 

Oh, and buy your wife a nice piece of jewelry. This may get you a little extra time before she throws you out of the house for getting prep dust on everything!

 

Good luck, have fun.