More Exposure For The Microfossil World

[Malone]

Thank you for the promotion of this subject!

[MarcoSr]

I see mention of use of acids like HCL and other chemicals like 30% Hydrogen Peroxide in posts in this topic.  You should never use the stronger acids no matter how diluted or high concentrations of the weaker acids or chemicals like 30% Hydrogen Peroxide in a home environment.  They are just too dangerous to the user to use outside of a lab environment and you will most likely destroy the fossils that you are looking to find.  In the US it can be difficult to purchase and ship the stronger acids.  Most chemical distributors won't ship the stronger acids to home addresses.  Liquid nitrogen works great at breaking down certain tough matrixes but no rational person would try to use liquid nitrogen at home so don’t use these other dangerous chemicals at home.  Stick to the safer home methods like water, freeze/thaw, 3% Walmart Hydrogen Peroxide, 5% and 10% vinegar (acetic acid content), laundry detergents etc. to break matrix down and free specimens.  Note in Virginia where I live I can’t even purchase 10% vinegar because of the acetic acid content.  These home methods may not work as quickly or even be able to break down some matrixes but they are much safer for you to use and usually don’t damage your specimens (you need to be careful with vinegar because acetic acid will destroy most invertebrate fossils and can dull or etch tooth enamel).  What you use depends on the matrix composition that you are trying to break down.

 

Marco Sr.

[Malone]

On 3/19/2013 at 6:27 PM, mikecable said:

Happy! Happy!!

Very Happy!!!

Thanks.

I'll do my best to make the category a winner,

Did I Say I'm happy!!!!!

I like the artwork in your title picture! It/He looks lonely.

[mossyfern9564]

I buy muriatic acid at home improvement stores.  It's hydrochloric acid, used for cleaning masonry, patios, etc..  I use it for both rocks and fossils I collect, diluting it as needed, depending on the type of rock or matrix.  I use large plastic coffee cans; one for the acid bath, and one with a neutralizing solution of baking soda and water.  The top for the acid bath is vented to release the carbon dioxide gas produced during the soaking process.  I use plastic tongs to move the cleaned object into the neutralizing solution.  The result there is some more carbon dioxide gas, basically table salt, and water.  Then I gently clean off any remaining softened rock or matrix with a toothbrush and rinse in clean water.   I do this outside, and always put the vented top on the acid bath container until I'm ready to remove my "victim" to the neutralizer, for the safety of my neighbor's cat, who has to examine everything on my porch, and any innocent creepy-crawlies who might fall in.  So far, I"ve had good luck; I live in an area in northeast TN that is high in limestone, and very close to the Virginia border.  I can purchase the muriatic acid in either state. 

[MarcoSr]

13 minutes ago, mossyfern9564 said:

I buy muriatic acid at home improvement stores.  It's hydrochloric acid, used for cleaning masonry, patios, etc..  I use it for both rocks and fossils I collect, diluting it as needed, depending on the type of rock or matrix.  I use large plastic coffee cans; one for the acid bath, and one with a neutralizing solution of baking soda and water.  The top for the acid bath is vented to release the carbon dioxide gas produced during the soaking process.  I use plastic tongs to move the cleaned object into the neutralizing solution.  The result there is some more carbon dioxide gas, basically table salt, and water.  Then I gently clean off any remaining softened rock or matrix with a toothbrush and rinse in clean water.   I do this outside, and always put the vented top on the acid bath container until I'm ready to remove my "victim" to the neutralizer, for the safety of my neighbor's cat, who has to examine everything on my porch, and any innocent creepy-crawlies who might fall in.  So far, I"ve had good luck; I live in an area in northeast TN that is high in limestone, and very close to the Virginia border.  I can purchase the muriatic acid in either state. 

 

From a safety perspective you don't want to have to depend on good luck.  You can have good luck 99 times in a row, but that one bad luck time can be catastrophic.  I love fossils but using dangerous chemicals are not worth the risk to me.  Also a lot of TFF posts come up in Google searches.  Would you be OK with a 12 year old kid using your method on his or her limestone?

 

Marco Sr 

[Miocene_Mason]

12 minutes ago, MarcoSr said:

Would you be OK with a 12 year old kid using your method on his or her limestone?

I’m 15 and we regularly use dilute HCl in chem. Acid can be nasty stuff, but dilution makes the acid. You should always use precautions when handling acid, especially eye protection and if your dissolving metals (like rocks with iron compounds in them) you should probably do it under a fume hood or outside with a gas mask. Information on acid is readily available on line and the substance itself is easily found and bought, education rather then censorship should be used. Always include a disclaimer. Btw this is not refuting either of you, just putting in my piece.

37 minutes ago, mossyfern9564 said:

basically table salt,

Not to be nit-picky but a believe it would be calcium chloride, which is not to be eaten. That will burn your insides. 

[MarcoSr]

On 5/17/2018 at 5:22 PM, WhodamanHD said:

I’m 15 and we regularly use dilute HCl in chem. Acid can be nasty stuff, but dilution makes the acid. You should always use precautions when handling acid, especially eye protection and if your dissolving metals (like rocks with iron compounds in them) you should probably do it under a fume hood or outside with a gas mask. Information on acid is readily available on line and the substance itself is easily found and bought, education rather then censorship should be used. Always include a disclaimer. Btw this is not refuting either of you, just putting in my piece.

Not to be nit-picky but a believe it would be calcium chloride, which is not to be eaten. That will burn your insides. 

 

It is not censorship to point out that you shouldn’t be using even dilute strong acids like HCl acid in a home environment to break down matrix.  Why encourage folks to use methods that in most cases will destroy the fossils that they are looking for and be dangerous to use if they don’t have the required experience and knowledge?  How many of the folks reading this post do you think have even had a basic high school chemistry course like you?  How many understand the inherent dangers with even dilute strong acids like HCl?  Do you think they understand what you mean by a dilute acid?  5% HCl acid is a dilute acid by definition.  Look at the information below from a LabChem safety data sheet for 5% HCl acid.  Note the "Major injury likely unless prompt action is taken and medical treatment is given".  5% HCl acid sure isn’t the same as 5% acetic acid in vinegar.  I don’t see people giving any safety warnings at all other than you.  Did you mention gloves, synthetic apron?  What you do in your home is up to you but don’t encourage others to do things that might be dangerous to them if they don’t have your experience or knowledge especially without any warnings.

 

HCl Acid, 5% V/V

 

 

Marco Sr.

[MarcoSr]

I have been breaking down matrix (sand, clay, limestone, sandstone, mudstone, shale, conglomerates etc.) for over twenty years and never used the stronger acids like HCl even in dilute concentrations.  The safer acids and methods may take longer, require multiple breakdowns and/or not 100% break down the tougher matrixes but they are much safer to use and don’t destroy your fossils.  I have at least 50 posts on TFF showing micro teeth from different matrix types.  I’ve broken down matrix from over a 150 sites worldwide.  To free up teeth in the .5 mm to a couple of millimeter range like in my posts you have to do a fairly good job of breaking the matrix down.  In twenty years of breaking matrix down, some type of matrix almost every week, I’ve screwed up or had accidents.  Luckily I was using 3% Walmart H2O2 and not lab grade 30% H2O2 or 5% or 10% vinegar and not 5% or 10% HCl acid.   I don’t care what folks post here on TFF, if you aren’t experienced using acids and don’t have the proper safety equipment, don’t even try to use even dilute HCl or other strong acids or high concentrations of the weaker acids in your home environment.  Also don’t use the really caustic cleaners that you can buy at a hardware store or Home Depot.  These cleaners can dissolve containers of certain material types, react violently with certain chemicals, release harmful vapors and/or cause severe eye, skin and respiratory tract injuries.  There are much safer detergents but I don't like to use detergents because I don't like dealing with the foam and lather of the soap suds in most of them.

 

Marco Sr.

[MarcoSr]

On 5/18/2018 at 8:18 AM, MarcoSr said:

I have been breaking down matrix (sand, clay, limestone, sandstone, mudstone, shale, conglomerates etc.) for over twenty years and never used the stronger acids like HCl even in dilute concentrations.  The safer acids and methods may take longer, require multiple breakdowns and/or not 100% break down the tougher matrixes but they are much safer to use and don’t destroy your fossils.  I have at least 50 posts on TFF showing micro teeth from different matrix types.  I’ve broken down matrix from over a 150 sites worldwide.  To free up teeth in the .5 mm to a couple of millimeter range like in my posts you have to do a fairly good job of breaking the matrix down.  In twenty years of breaking matrix down, some type of matrix almost every week, I’ve screwed up or had accidents.  Luckily I was using 3% Walmart H2O2 and not lab grade 30% H2O2 or 5% or 10% vinegar and not 5% or 10% HCl acid.   I don’t care what folks post here on TFF, if you aren’t experienced using acids and don’t have the proper safety equipment, don’t even try to use even dilute HCl or other strong acids or high concentrations of the weaker acids in your home environment.  Also don’t use the really caustic cleaners that you can buy at a hardware store or Home Depot.  These cleaners can dissolve containers of certain material types, react violently with certain chemicals, release harmful vapors and/or cause severe eye, skin and respiratory tract injuries.  There are much safer detergents but I don't like to use detergents because I don't like dealing with the foam and lather of the soap suds in most of them.

 

Marco Sr.

 

 

If you don't believe me the below page is from Welton and Farish 1993:

 

Edit: Note I should have removed the part below about using Kerosene.  Thank you Jean-Pierre for your comments below.  I had posted the Welton/Farish page for its discussion on the use of acids to break down matrix.  Kerosene is smelly and flammable.  I have used it in the past but there are other methods that are as effective in breaking clay down that don't require the use of a flammable, smelly chemical.

 

 

Marco Sr.

Edited May 19, 2018 by MarcoSr
added note about kerosene

[mossyfern9564]

 

Sodium bicarbonate, or baking soda, reacts with hydrochloric acid to produce sodium chloride (table salt), water, and carbon dioxide.

 

NaHCO3 + HCl = NaCl + H2O + CO2

 

As for whether I would feel safe letting a 12-year-old use this method, yes I would, with proper supervision.   Again, I'm talking about dilute HCl acid.  Hydrochloric acid is the acid component in the gastric acid in our stomachs. 

 

My intention wasn't to seek argument, nor to encourage anyone else to do what I do; only to describe my method. Also, when I said I'd had good luck so far,  I meant with the results I've gotten with the method, not that I depend on luck for safety.    

[Miocene_Mason]

27 minutes ago, mossyfern9564 said:

 

Sodium bicarbonate, or baking soda, reacts with hydrochloric acid to produce sodium chloride (table salt), water, and carbon dioxide.

 

NaHCO3 + HCl = NaCl + H2O + CO2

 

As for whether I would feel safe letting a 12-year-old use this method, yes I would, with proper supervision.   Again, I'm talking about dilute HCl acid.  Hydrochloric acid is the acid component in the gastric acid in our stomachs. 

 

My intention wasn't to seek argument, nor to encourage anyone else to do what I do; only to describe my method. Also, when I said I'd had good luck so far,  I meant with the results I've gotten with the method, not that I depend on luck for safety.    

Sorry I misread, I thought you were talking about using it on Limestone (calcium carbonate). 

 

BTW I have never used HCl on fossils and don’t suspect I will have that need. I find concentrated acetic acid is too strong for my purposes so I have to dilute it to below 5%.

[jpc]

A quick comment for those who read all of marco sr's posted page form Welton and Farish 1993.  they suggest kerosene for dissolving clay.  This has gone by the wayside as an approved technique because, well, kerosene is nasty and flammable stuff.  I have used any commercial citrus based cleaner to break down clay and it seems to work just fine.  And smells so much nicer.  

[MarcoSr]

On 5/18/2018 at 4:59 PM, jpc said:

A quick comment for those who read all of marco sr's posted page form Welton and Farish 1993.  they suggest kerosene for dissolving clay.  This has gone by the wayside as an approved technique because, well, kerosene is nasty and flammable stuff.  I have used any commercial citrus based cleaner to break down clay and it seems to work just fine.  And smells so much nicer.  

 

Jean-Pierre

 

Thank you for the comment.  I had intended to say something about the kerosene but it totally slipped my mind.  I'll edit my post.  I have used kerosene in the past to break down clay and agree it is nasty and smelly stuff and there are other methods that work as good or better.

 

EDIT:  I should point out that there are a number of matrix break down methods that were used in the past that are mentioned in books and papers that are no longer used for safety reasons.  There was an industrial cleaner that researchers mention in a number of papers that was used to break down shale years ago.  I researched the cleaner and found that it was no longer manufactured.  It was nasty and dangerous and removed from the market for safety reasons in its intended use which wasn't breaking shale down.  It has been replaced by much safer chemicals for their intended use which are actually more effective as industrial cleaners.   The research that I did on this product and others is why I stay away from industrial cleaners or even some home use cleaners for safety reasons that could be used to break down matrix but most likely would also damage or destroy fossils.

 

 

Marco Sr.

[MarcoSr]

17 hours ago, mossyfern9564 said:

 

Again, I'm talking about dilute HCl acid.  Hydrochloric acid is the acid component in the gastric acid in our stomachs. 

 

 

 

When you work with acids you should use a safety sheet that addresses the specific concentration of acid that you want to use to understand the risks and safety equipment/precautions needed.  Even dilute (as you are using the term as a concentration of HCl acid in patio and masonary cleaners) HCl is still extremely dangerous to your eyes.

 

Marco Sr.

[KimTexan]

@MarcoSr I often don’t take much of what you said into consideration for others. For myself it is par for the course.

I have a chemistry minor as part of my science degrees. I work at a university. I work with very toxic and caustic chemicals on a regular basis. I have had a lot of training on the useage of these chemicals and am required to take annual refreshers in chemical safety. Everything you have said is absolutely spot on. 

Like Marco said if you do chose to work with a chemical please read start by reading the SDS (Safety Data Sheet Formerly MSDS) for the specific concentration being used before you even open the container. If you’ve already opened it go read it now before continuing to use it.

This is a link where you can find most SDSs at.  

https://www.sigmaaldrich.com/safety-center.html

Also, every chemical should have an NFPA/HMIS label or similar hazards rating on the container. Familiarize yourself with the label and what the different numbers or levels of danger mean. Here is the rating guide.

 

All rating scales are not the same. HMIS and NFPA are generally the most common standards. So don’t be confused and think a GHS rating is the same as NFPA. The diamond with a person inside it is the GHS symbol should you see it.

 

Educate yourseld, be careful and be safe.

[TroyB]

Anytime I visit a fossil site, I always bring back a gallon ziplock or two, of the matrix that the fossils are coming out of. Breaking it down, only requires a 24 hour submerged bath in 3% Hydrogen Peroxide, for most the places I go. Then I use 4-5 sift sizes. (1/2", 1/4", 1/8", 1/16" and 1mm). What ever falls through the 1mm, I usually use a gold pan technique, to remove the remaining dirt. after that I allow the siftings to set out in the sun to dry. This seems to setup or harden the fossils a vbit. Then, bag and tag them and when a rainy day comes along, I go thru them under the microscope. I find many micro teeth this way, from the Eocene glauconite and Cretaceous marl type matrix's. And it is very environmentally friendly as H2O2 (Hydrogen peroxide) breaks down to Water and Oxygen byproducts..

 

[Hubertus68]

Dear forum members,

 

I'm a citizen scientist working on fossil bryozoa of the Maastrichtian type locality: Maastricht in the Netherlands. The uppermost cretaceous deposits there contain an amazingly well preserved fauna (of not only bryozoa) that I began to study a few years ago. Several hundred bryozoan species are documented from these deposits and many are yet to be described. The size of these mostly small colonies ranges from less than a mm up to 20 cm. The single cells (zooids) are much smaller and can only be examined by the use of SEM-technology. In this topic I want to show you some of the SEM-images we made as well as some micro-photographs that I took with an old Leitz binocular and a simple pocket camera. Enjoy the wonderful world of these fascinating but mostly ignored fossils!

[Hubertus68]

By the way, I prepare most of the fossils by using an ultrasonic cleaner. This is not suitable for every specimen but for the most.

The very fragile pieces cannot be prepared properly.

[vellis]

Nice SEM pics.    And +1 on the ultrasonic cleaner, I bought mine fairly cheap at Harbor Freight, I think.  I’m sure there are much better ones, but this one does the job.

 

I normally have a really fine mesh bag (maybe 1 or 2 gallon)  not sure of the numbers, that I use to get all the “dirt” out and leave gravel.  I’ll fill it up and then either let the creek run through it, or drag it around in the creek to help the process.  

 

Where I go to in Sherman for my micros, there is mostly mud and not hard matrix.

 

 

[Matt Stratton]

Micro level. Chandler bridge formation. Summerville SC. Jewelers magnification. don't know the power. Cool huh?

[ALBob]

I am excited about this area. I was under the impression from the internet that micro fossils were limited to those that are microscopic. I have about 50 species of what has been termed dwarf fossils by Kansas paleontologists writing up their finds in the layer of rock from which I took my specimens. All are about 5 mm or less in size. Will post some photos when I have them prepared.

[GorgonGal]

I'm a contract microfossil preparator (but also prep larger fossils), so have found this thread very interesting! I'm based in South Africa where we have a lot of therapsids and Permian-Triassic specimens. I've honestly never tried to prepare a fossil using chemicals, and only used mechanical means. I'm interested to learn a bit more about the chemical preparation. I did ask someone about it once when I was first starting as a preparator and was told "South African matrix is much harder than American, so chemical prep won't work here"  which I now seem to think may have not been true! I'm currently working on a scalenodontoides (Late Triassic) which has a large amount of matrix. Taking it off mechanically has taken over 2 years so far and I'm probably only halfway there. Wondering if chemical matrix removal would be easier? Obviously prepared to set myself up properly so all safety precautions will be taken. I will search around the forum a bit more for info. 

 

As for micro-preparation, I've honed my skills in and specifically enjoy teeth. I've attached a picture of a nest of youngina capensis (mm scale bar) that I worked on in 2018/2019 and the picture was taken through the eyepiece of my microscope. Here we are not allowed to collect, keep or sell fossils as a private citizen. So this piece came from a museum and I think was identified before it was prepared. I think the only trick of the trade that I have developed in the prepration side of these tiny creatures is to make sure your stylus is sharp!