Question about removing pyrite

[KimTexan]

I have something of a cephalopod hash plate  from the Britton Formation in Collin County Texas that I am working on. I don’t have great tools and so I’m prepping this completely manually, by hand. It has a layer of pyrite that is pretty tough to work with by hand.

 

I am wondering, could I use Iron Out to soften or remove the pyrite without doing harm to the fossils or the cohesiveness of the plate? If so what would be the best way and dilution to use it at?

 

 

These are pics of the little plate.

I consider this the bottom. You can see the thin gray layer here and there. I’ve been slowly chipping away at it. 

Maybe I could brush Iron Out just on the spots of pyrite.

 

This is the top. It has a bunch of little ceholopods on it. There is a mix of heteromorphs, baculites and ammonites along with some tiny, adorable gastropods.

This pic it is partly wet, but the pyrite is covered with a red mud on the left half and top half of the plate.

 

The bottom is a bit easier to work with since the cephalopods aren’t packed like sardines as they are on the top side. I can probably get rid of most of it on the bottom without too much damage, but the top is another matter.

[Ludwigia]

I suppose you could experiment first on a small spot. Never tried it myself. Pyrite can really be a pain in the pettuti sometimes. Is there a separating layer between pyrite and fossils or does it go straight into the fossils as well?

[Ptychodus04]

You have here a typical mudstone concretion from the Scipinoceras gracile (this are the little straight ammonites in your block) Zone. They are a beast to prep at times even with pneumatic tools. The outer brown layer is kind of soft but you will get to an extremely hard grayish layer soon. That part will make you cuss!

 

I don’t recall seeing pyrite on any of these in the past but it isn’t impossible. That being said, mechanical removal is your only choice for pyrite. Iron Out can be used to clean pyrite, but it takes a nuclear warhead to remove it.

[KimTexan]

9 hours ago, Ludwigia said:

Is there a separating layer between pyrite and fossils or does it go straight into the fossils as well?

Some of it seems to be on the surface. It’s hard to tell if it goes into the fossils. Some of the ones it was on just crumbled. I don’t know if that was poor preservation or pyrite. It behaved a bit like the pyritized fossils I’ve found elsewhere.

 

2 hours ago, Ptychodus04 said:

You have here a typical mudstone concretion from the Scipinoceras gracile (this are the little straight ammonites in your block) Zone. They are a beast to prep at times even with pneumatic tools. The outer brown layer is kind of soft but you will get to an extremely hard grayish layer soon. That part will make you cuss!

 

I don’t recall seeing pyrite on any of these in the past but it isn’t impossible. That being said, mechanical removal is your only choice for pyrite. Iron Out can be used to clean pyrite, but it takes a nuclear warhead to remove it.

I could be wrong about it being pyrite. On the bottom it is sparklely. On the top it isn’t sparklely, but much harder.

I have a lot of stuff from the Scipinoceras gracile zone. It’s probably the closest good fossil hunting spot to where I live that I have found so far. I’ve only lived here a yr now. So I’m still checking out new spots. This is the first time I have found what I think is pyrite covering items from there.

There is some other mineral that precipitated on the surface of some of the material there, which looks a bit like the stuff on this specimen, but I can usually see whiteish gray to clear crystals. This looks different than that stuff.

Here is a pic of the stuff that precipitates onto the surface. I think it may be gypsum, but I don’t know for sure. It looks pretty cool.

 

[ynot]

Looks gypsum to Me.

Nocs plate of crystals too.

[KimTexan]

Thank you for the confirmation or at least validation.

I can’t think of any other common crystal in the area which would form crystals so easily and rapidly under such conditions, over a season. The next big rainy season most of the layer will be washed away.

We have calcite in abundance, but I think it would take longer to form crystals of that size in a short period.

[Ptychodus04]

4 hours ago, ynot said:

Looks gypsum to Me.

Nocs plate of crystals too.

Yep. Gypsum it is. If the fossils have gypsum in them, they will be very unstable as you describe. 

[KimTexan]

2 hours ago, Ptychodus04 said:

Yep. Gypsum it is. If the fossils have gypsum in them, they will be very unstable as you describe. 

There wasn’t gypsum on the surface of this concretion. So when it precipitates on the surface of the rocks I assume it is precipitating from inside the rock it is on. 

Most of the stuff I’ve found out there if it is whole it is pretty stable. The crab appendages aren’t terribly stable, but I think that’s common.

There are 2 medium ammonites that seem fragile in the area of the Britton I hunt in. One never has gypsum on it. I think those are Metoicoceras. The other I believe is Metegenoceras acutum.  Most of the few dozen I have found have a layer of gypsum on the surface. I have never found a whole one. The most I have of those is a half. So I believe the part about the gypsum making them unstable. I think the only way I’d find a whole one is if it got dug up and hadn’t been exposed for too long.

[Ptychodus04]

If you’re in the Sciponoceras gracile Zone, you can be finding Placenticeras

 

or Metengonoceras

along with your Metoicoceras.

 

Placenticeras is far more common than Metengonoceras.

 

It is very common to find partial Metoicoceras and Placenticeras in the Britton as the phragmacones get crushed and broken off. The Metengonoceras I have found have been the opposite with phragmacones preserved and living chambers gone.

[Ptychodus04]

Ultimately, the concretions can yield very nice fossils. Sometimes they are calcified.

 

[KimTexan]

@Ptychodus04

Thank you for sharing pics!! It is so very helpful to see a prepped example.

 

Also, the ammonites are helpful to see. What kind is the smaller one? Very nice.

Is the big one a Metengenoceras acutum?

 

I saw your post before, but never saw the pics for some reason.

I have quite a few of those baculite plates. Many of them have tiny gastropods on them. Some are phosphatized, black and shiny. Some are a lovely brown. There are a bunch of small heteromorphs and other cephalopods along with the baculites. I never finish prepping them though. One hash plate has at least 7 species on it. Some of the baculites are needle thin. They’re cool pieces, but my prep skills and ability with the tools I have don’t do them justice.

Maybe on day I can afford pneumatic tools.

 

I don’t really know the names of the cephalopods in the Britton that well to the degree I can know them upon sight. So I could be totally wrong about the medium sized ones.

 

I am not sure I have seen either of the two you shared out where I hunt. If I have maybe what I have seen is so damaged and distorted they don’t resemble what you have there.

 

There are fragments of 3 genus I commonly find out there. Below are pics of two of them.

 

I find lots of fragments of these. There all this size or smaller. I can’t get the rest of the matrix off. It’s hard like concrete. I’m not patient enough to sit and Grand or sand the matrix down to the fossil. Those cuts are from my diamonds wheel attachment for my Dremel. Pretty crude work.  

I assume this is a type of Metoicoceras.

 

This is the keel.

 

 

 

Placenticeras? Really? I’m so green at trying to ID stuff!! I get a bit frustrated with myself at times. The book (Emmerson and Akers) I have does not mention Placenticeras being found in that zone. The paper I have by Kennedy didn’t mention it in the list for the Eagle Ford either. I think the list was for the Sciponoceras gracile zone. I could be wrong. I know the lists are not 100% inclusive.

Now that you say Placenticeras it does look a lot like one of them I found in Arlington only I can’t see any ribs or tubercles on any of the pieces I have.

 

I find lots of fragments of these below. This is the most complete piece I have found. I found all of it in the ground, but the other was something like calcite dust, but this part remained. It is still covered with the calcite precipitate. These are very thin with a sharp keel. Granted this one is a bit flattened, but they’re all very thin.

This is what I believed were Metengenoceras, but maybe I am wrong. Maybe it is a type of Placenticeras. I’m a complete novice at ID.

Do you have a reference paper or book saying they are found in the Sciponoceras gracile zone? Evidently I need further education on the matter.

 

 

 

Hum, I’m not sure what to think.

Here are the dimensions. It may be 55% complete so I would think the diameter would be correct.

But I am not sure if the Wh would be accurate. It may be a bit too small.

 

Diameter - 143 mm 

Whorl height - 80 mm

Whorl breadth - 17 mm, granted it is slightly flattened.

 

The Wh/D ratio is 55.9%. So maybe it would be in the low 50s. If basing type only upon that it may fall in the Placenticeras camp.

[Ptychodus04]

@KimTexan, is the Emerson and Akers reference “Texas Cretaceous Ammonites and Nautiloids”? Although it doesn’t list Placenticeras in the Britton, I have found many that compare favorably to P. cumminsi in the S. gracile Zone. That’s my first ammonite pic (overall features as well as suture pattern are right).

 

My second pic is Metengonoceras acutum.

 

Your first ammonite is Metoicoceras geslinianum. Your second ammonite is Metengonoceras acutum most likely (you can tell it is an engonocerid from the partial suture preserved) and M. acutum is the only one from the S. gracile Zone.

 

The “baculites” you are seeing are the ammonites that this Zone is named for: Sciponoceras gracile.

 

There are a few different heteromorphs in the formation and they are very sexually dimorphic so you can have two very different looking ammonites that are in fact the same species.

 

Dont get frustrated. Identification is hard. Always be ready to revise your identifications if further info or knowledge comes to light for you.

 

My prepping started with small hand tools and it took me 6 years to even begin buying pneumatic tools. Take things as far as you are capable, they can always be worked on more later.

[KimTexan]

23 hours ago, Ptychodus04 said:

@KimTexan, is the Emerson and Akers reference “Texas Cretaceous Ammonites and Nautiloids”?

Yes, that is the book I have.

 

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My second pic is Metengonoceras acutum.

 

Your first ammonite is Metoicoceras geslinianum. Your second ammonite is Metengonoceras acutum most likely (you can tell it is an engonocerid from the partial suture preserved) and M. acutum is the only one from the S. gracile Zone.

Thank you very much for the IDs genus confirmations and the species on the Metoicoceras!!!! Since I am such a novice at ID I don’t trust myself to ID an ammonite that is new to me where I don’t have a more experienced persons input. But I am happy to hear I got the genus right on both. Yay!!! I knew if it was that it must be the M. acutum. I lost count on how many partials I pick up out there.

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The “baculites” you are seeing are the ammonites that this Zone is named for: Sciponoceras gracile.

I had figured the baculite ID out. It is kind of hard to miss why they call it the Sciponoceras gracile zone. They are everywhere out there.

 

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There are a few different heteromorphs in the formation and they are very sexually dimorphic so you can have two very different looking ammonites that are in fact the same species.

I have read a little about the dimorphisms. I’m not sure I can tell them apart.

On the one plate I found I am pretty sure it has at least 2 species of Allocrioceras. One of them is about 3 cm. Several other are half that.

Then there may be 2 species of The same plate has Worthoceras on it. I’m not sure which one(s) yet. 

I think there is a Metaptychoceras reesidei on there too. There is one I am not sure what it is, because it looks like it has 2 shafts running parallel kind of like a 2 parallel shaft Metaptychoceras, but it doesn’t fit the description of M. reesidei. I’d say it is an M. annultum, but I can’t see a 3rd shaft. Both shafts are smooth as far as I can see, but M. annultum aren’t found in the Britton to my knowledge. It isn’t fully processed so there could be a 3rd shaft there.

 

Do you know if M. annultum 

or something similar to it are in the Britton?

 

There is a partial Metoicoceras on it.

There is also what I believe is a Pseudocalycoceras angolaense (Spath, 1931). Eucalycoceras seems to be used for Pseudocalycoceras. I’m a bit confused with the mixing of these 2 names. I am not sure if it goes by one or the other or if they are 2 different genus. Do you know?  The Pseudocalycoceras angolaense has 3 rows of tubercals on the keel. I can’t see the flanks yet to see if there are tubercles on the flanks.

Then of course there are numerous Sciponoceras gracile on it.

There must be at least 2 dozen cephalopods on the plate. It is barely processed, but there are at least 7 types of them so far as I can figure.

I am learning a lot about the genus as I go and try to figure them out. 

 

I have papers and a book for cephalopod ID, but nothing for gastropod ID. Do you know of any papers for gastropods in Texas kind of like Kennedy’s papers or a book?

I keep finding the most adorable tiny gastropods and there seems to be quite the variety.

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Dont get frustrated. Identification is hard. Always be ready to revise your identifications if further info or knowledge comes to light for you.

Knowing that I got the one right gave my confidence a bit of a boost.

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My prepping started with small hand tools and it took me 6 years to even begin buying pneumatic tools. Take things as far as you are capable, they can always be worked on more later.

That is encouraging to hear.

Thank you so very much for your responses. They have been very helpful in educating me in the Britton. 

 

I gather you prep stuff for people, but I don’t know if that is your profession or a side job. Someone messaged me asking for names of people who do prep work. I gave her your name and someone else’s and told her that if you didn’t do it you could probably refer her to someone.

 

Is it your profession?

 

[Ptychodus04]

@KimTexan can you send a pic of the plate with all the cool stuff going on?

 

There’s a couple good references on fastripods from HGMS. I believe they are “Texas Cretaceous Gastropods” Volumes 1 and 2. I have them so will try to pull them out and verify.

 

I do prep for people. It is a side thing right now. Sometimes it doesn’t feel like a side thing though! Right now I have 4 different prep jobs that I’m working on! I prep so much that I don’t even get to collect anymore. That’s ok because I still get to play with fossils.

[KimTexan]

I posted these a while back. I get tired of working on these things. The fossils are so small and the matrix is so hard to work with that I chose to leave it as is and go do something else.

Today was a rainy day so I couldn’t go out collecting like I wanted to. I worked on a different Britton cephalopod plate with a whole other set of cephalopods. It’s the original pic of this post about prep.

These are from one plate.

There is a fish vert.

 

Here you can see a gastropod on bottom left next to an Allocrioceras. There are several more on the plate on this side and the other side too.

Underneath the aforementioned Allocrioceras to the right side is what I believe is a Worthoceras.

Above that is a kind of chubby end of some cephalopod that I think is a heteromorph. I can’t tell yet, but it’s fatter than any one I’ve seen and it doesn’t look like a gastropod. I’m thinking maybe a fat Worthoceras. Needs more work to make a determination.

Above that and to the left is what I believe is the Pseudocalycoceras angolaense. It has 3 rows of tubercles. It is broken. I can’t tell how much of it is there.

There are baculites fragments all over the place.

 

This is is a sideways view of the same thing. Only closer and a little to the left. There are 2 gastropods next to each other.

 

This is the flip side. Matrix is actually lighter.  Big Allocrioceras. There are a number of baculites here too. 

Top side from another angle.

 

I took these tonight. Top side of first half. I found it in the field in 2 pieces. First baculite or fossil I ever saw in the Britton was this plate split in 2.

There is part of a Metoicoceras on the top right under everything.

 

The bottom Tom side of it.

 

The other half of it. It is like a different block of the neighborhood. Looks totally different and has much less variety. Top side 2nd half. I think there is part of a Worthoceras on the bottom right and a small Allocrioceras top center.

 

The bottom half is not very interesting yet. I’ve only exposed the ends of a few baculites.

 

It has been a number of months months since I looked at this plate. The thing I thought was a Metaptychoceras doesn’t look like one now. It’s not fully prepped out so it is very hard to tell what it is. Probably another Worthoceras. It’s got a baculite and something else lying over it.

 

Many of the cephalopods are not whole, but I think it is pretty cool for the first fossil I ever found in the Britton.

 

I have a number of these plates with a lot going on diversity wise. They’re all cool and they take up a lot less space than my other ammonites, besides all my little pyratized ones from the Duck Creek.

[KimTexan]

Oh bummer about not getting to collect anymore. I’d rather be collecting anyday. Being outdoors in nature is my little piece of sanity since I work indoors in the city. I hate that part. I help people get a new lease on life with organ and bone marrow transplants so it is rewarding many times. 

[Ptychodus04]

That does have a lot going on! This is the reference I was referencing. 

 

There’s only one. There’s 2 regarding bivalves.

 

I still get outside, just not to collect very often. My boys like to camp and hunt so the time I get, we spend doing that. If I get to tag on a fossiling stop, I usually do it then.

 

I also need time away from the indoors and the hustle of city life.

[KimTexan]

Thank you for the reference.