Removing Fossils From Siltstone

[JimB88]

Im having difficulty with a incredibly fossiliferous siltstone. The matrix forms no plane of weakness with the fossils. Ive been using a dentists pick and small chisel without much success. The fossils are siliceous so if there is a way to dissolve siltstone the fossils should be okay. Anyone have idea's (that dont involve any kind of explosive )

[Auspex]

You might experiment with running water and a scrub brush.

[MikeD]

Try hydrogen peroxide. It might work.

[JimB88]

Thanks guys!

Ive been using water and a tooth brush, which does remove loose eroded material, but not the matrix. I'll have to give hydrogen peroxide a try.

[micropterus101]

Pictures would help. If its anything like the siltstone here in Wa you could use a small airscribe or air abrasive. I just worked out some gastropods with my airscribe and it worked great. If you are just trying to expose the fossils but keep them in the matrix dont use water or any other liquid. the process of drying , wetting , drying really breaks down the siltstone and it will crumble. Good if you are trying to totally free the fossils from the matrix. bad for keeping matrix specimens.

[Harry Pristis]

Im having difficulty with a incredibly fossiliferous siltstone. The matrix forms no plane of weakness with the fossils. Ive been using a dentists pick and small chisel without much success. The fossils are siliceous so if there is a way to dissolve siltstone the fossils should be okay. Anyone have idea's (that dont involve any kind of explosive )

You can boil these fossils in a solution of Quaternary-O, a super-detergent quaternary ammonium. Directions on page 168 of FOSSILS FOR AMATEURS by McFall & Wollin.

You can clean them with an ultrasonic cleaner.

[JimB88]

You can boil these fossils in a solution of Quaternary-O, a super-detergent quaternary ammonium. Directions on page 168 of FOSSILS FOR AMATEURS by McFall & Wollin.

You can clean them with an ultrasonic cleaner.

I have never heard of that. Where does one get Quarternary-o? I'll have to try it on an extra piece. Thanks!

[pleecan]

Air abrasion can work wonders given the proper , nozzle size, media type , and air pressure.

[siteseer]

Im having difficulty with a incredibly fossiliferous siltstone. The matrix forms no plane of weakness with the fossils. Ive been using a dentists pick and small chisel without much success. The fossils are siliceous so if there is a way to dissolve siltstone the fossils should be okay. Anyone have idea's (that dont involve any kind of explosive )

There is an article about preppers experimenting with DMSO to remove sandstone matrix. It acts as sort of a lubricant seeping in between particles so that they simply fall away from the specimen and each other. They reported varying levels of success with rock of many sites. A friend read the paper and tried it but it did not do anything for him.

[FossilDAWG]

I have never heard of that. Where does one get Quarternary-o? I'll have to try it on an extra piece. Thanks!

Unfortunately Quaternary-O has not been manufactured for many years. It was almost magical in its ability to remove shale from calcareous fossils. Recently I noticed under the sink in my lab a bottle of a detergent called "Oakite", and I noticed on the label that the active detergent is quaternary ammonium (just like Quaternary-O). I experimented with some fossils that had already been attacked with a toothbrush and water to little avail, and to my amazement a 30% solution of Oakite seems to be very effective at removing the shale. I've had good results just letting the fossils soak for a few days, but things go faster if you can heat the solution (in a well ventilated area) almost to boiling. If you Google "Oakite" you will find info on the manufacturer and perhaps local dealers, it's used to clean refrigeration equipment I believe.

Don

[FossilDAWG]

There is an article about preppers experimenting with DMSO to remove sandstone matrix. It acts as sort of a lubricant seeping in between particles so that they simply fall away from the specimen and each other. They reported varying levels of success with rock of many sites. A friend read the paper and tried it but it did not do anything for him.

I saw that paper and tried DMSO as well, and like your friend had no success. Must have to do with the chemistry of how the rock is consolidated I guess.

Don

[Shamalama]

Unfortunately Quaternary-O has not been manufactured for many years. It was almost magical in its ability to remove shale from calcareous fossils. Recently I noticed under the sink in my lab a bottle of a detergent called "Oakite", and I noticed on the label that the active detergent is quaternary ammonium (just like Quaternary-O). I experimented with some fossils that had already been attacked with a toothbrush and water to little avail, and to my amazement a 30% solution of Oakite seems to be very effective at removing the shale. I've had good results just letting the fossils soak for a few days, but things go faster if you can heat the solution (in a well ventilated area) almost to boiling. If you Google "Oakite" you will find info on the manufacturer and perhaps local dealers, it's used to clean refrigeration equipment I believe.

Don

Hmmm... Sounds like interesting stuff. So I'm looking up stuff from "Oakite" and that seems to be a brand name rather than a specific solvent. I found one site that lists many different products like "Oakite 100", "Oakite 443" etc. Can you see any more detail on your bottle (if you still have it)?

[JimB88]

Unfortunately Quaternary-O has not been manufactured for many years. It was almost magical in its ability to remove shale from calcareous fossils. Recently I noticed under the sink in my lab a bottle of a detergent called "Oakite", and I noticed on the label that the active detergent is quaternary ammonium (just like Quaternary-O). I experimented with some fossils that had already been attacked with a toothbrush and water to little avail, and to my amazement a 30% solution of Oakite seems to be very effective at removing the shale. I've had good results just letting the fossils soak for a few days, but things go faster if you can heat the solution (in a well ventilated area) almost to boiling. If you Google "Oakite" you will find info on the manufacturer and perhaps local dealers, it's used to clean refrigeration equipment I believe.

Don

Hmm, that sounds promising - there was no damage to the fossils correct? Thanks for the tips everybody.

[oilshale]

I saw that paper and tried DMSO as well, and like your friend had no success. Must have to do with the chemistry of how the rock is consolidated I guess.

Don

First of all, DMSO (Dimethyl sulfoxide) is a nasty stuff. DMSO by itself has low toxicity. Because DMSO easily penetrates the skin, substances dissolved in DMSO may be quickly absorbed. A drop of DMSO onto your skin will cause garlic like taste in your mouth! For instance, a solution of sodium cyanide in DMSO can cause cyanide poisoning through skin contact. So please, wear thick rubber gloves and not the ordinary nitrile gloves! You don't want to have DMSO in your body.

But my main point is, it won't work! DMSO is an excellent solvent for inorganic salts as well as for organic material. But DMSO will not attack normal siltstone. In some rare cases, it is possible to soften and even to disintegrate oil shales with DMSO (but just if the organic content is high enough).

[Wakaritai]

Can you post pics of the specimens in question? I'd like to see if its similar to some that I have because I've wondered the same things before.

[oilshale]

Unfortunately Quaternary-O has not been manufactured for many years. It was almost magical in its ability to remove shale from calcareous fossils. Recently I noticed under the sink in my lab a bottle of a detergent called "Oakite", and I noticed on the label that the active detergent is quaternary ammonium (just like Quaternary-O). I experimented with some fossils that had already been attacked with a toothbrush and water to little avail, and to my amazement a 30% solution of Oakite seems to be very effective at removing the shale. I've had good results just letting the fossils soak for a few days, but things go faster if you can heat the solution (in a well ventilated area) almost to boiling. If you Google "Oakite" you will find info on the manufacturer and perhaps local dealers, it's used to clean refrigeration equipment I believe.

Don

I would guess Quaternary-O being similar to Rewoquad W3690 (tradename of Witco Surfactants). This is a quaternary cationic surfactant which can be used to disintegrate soft marls and clays. Can be purchased from Krantz in Germany http://www.krantz-online.de/de/online_shop/produkte/16.html

"Rewoquad

Put in your fossils in the Tensid Rewoquad; at the following processes the soft particles like marl will get off itself. P.e. at Foraminiferes, Brachiopods and more. Also you can clean with it Solnhofen plates p.e.. 1 liter

Item Number: S 62 · delivery status:

23,50 €

19% VAT included

plus Shipping and Handling"

Edited April 26, 2010 by oilshale

[pleecan]

I am in agreement with oilshale .... DMSO is nasty stuff, with out proper protection... it can easily penetrate skin and carry potential other agents / poisons into the body / blood stream.

[JimB88]

Can you post pics of the specimens in question? I'd like to see if its similar to some that I have because I've wondered the same things before.

Ive posted pics (albeit bad ones) in the gallery section. The grayish rock is the siltstone the stuff in the tan rock is calciferous shale I believe.

My pics

[FossilDAWG]

Hmmm... Sounds like interesting stuff. So I'm looking up stuff from "Oakite" and that seems to be a brand name rather than a specific solvent. I found one site that lists many different products like "Oakite 100", "Oakite 443" etc. Can you see any more detail on your bottle (if you still have it)?

The bottle is labeled "Oakite Sanitizer I". It's a 20% solution of quaternary ammonium something or other (I don't have it here right now and don't recall the rest of the active ingredient). I got good results diluting it 3-fold, cleaning shale from some cystoids and brachiopods from the Benbolt formation, brachiopods and trilobites from the Verulam (Ontario), and a bunch of stuff from Dudley (English Silurian). I googled "Oakite sanitizer" and got a link to the sanitizer IV version, which is also a quaternary ammonium detergent. Let us know how it works out for you if you try it.

Don

[Harry Pristis]

The bottle is labeled "Oakite Sanitizer I". It's a 20% solution of quaternary ammonium something or other (I don't have it here right now and don't recall the rest of the active ingredient). I got good results diluting it 3-fold, cleaning shale from some cystoids and brachiopods from the Benbolt formation, brachiopods and trilobites from the Verulam (Ontario), and a bunch of stuff from Dudley (English Silurian). I googled "Oakite sanitizer" and got a link to the sanitizer IV version, which is also a quaternary ammonium detergent. Let us know how it works out for you if you try it.

Don

I did a little reading about quaternary ammonium yesterday. It seems that it (the cation) has a wide variety of uses in cosmetics and disinfectants. Benzylconium chloride is one such q-ammonium compound (or "quat" in the industry) which is a common ingredient in many shampoos and other cosmetics. They seem to be fairly non-hazardous.

I note that the Wal-Mart store brand aerosol disinfectant is one percent quats and thirty-seven percent alcohol.

Today, I went to the local surplus/salvage warehouse, and looked at an array of disinfectants/cleaners with q-ammonium components. Apparently, these products are used to disinfect surfaces in hospitals and other institutional settings. There were a half-dozen or so different brands with different formulations. The one with the most active ingredients (about 15% total) had two different q-ammonium compounds. The price was about $8.00 for a gallon jug (it's surplus, remember).

I was tempted, but I just don't have anything (mudstone, shale) on which to experiment. I'm passing on what I saw for your information. You might get such a product from your local janitorial supply house.

Edited April 28, 2010 by Harry Pristis

[oilshale]

I did a little reading about quaternary ammonium yesterday. It seems that it (the cation) has a wide variety of uses in cosmetics and disinfectants. Benzylconium chloride is one such q-ammonium compound (or "quat" in the industry) which is a common ingredient in many shampoos and other cosmetics. They seem to be fairly non-hazardous.

I note that the Wal-Mart store brand aerosol disinfectant is one percent quats and thirty-seven percent alcohol.

Today, I went to the local surplus/salvage warehouse, and looked at an array of disinfectants/cleaners with q-ammonium components. Apparently, these products are used to disinfect surfaces in hospitals and other institutional settings. There were a half-dozen or so different brands with different formulations. The one with the most active ingredients (about 15% total) had two different q-ammonium compounds. The price was about $8.00 for a gallon jug (it's surplus, remember).

I was tempted, but I just don't have anything (mudstone, shale) on which to experiment. I'm passing on what I saw for your information. You might get such a product from your local janitorial supply house.

The surfactants used to remove marl or mudstones are quaternary ammonium surfactants, but they are not Benzalconium surfactants and belong to a slightly different class. They are amino-ethyl-Imidazolinium surfactants. Rewoquat W3690 for example is 1-Methyl-2-Noroleyl-3-Oleic-Aminoethyl-Imidazolinum-Methosulfate. Benzalconium surfactants won't work (at least the ones I tried didn't work).

Here is a link (sorry, the page is in German).

http://www.fsb-shop.com/assets/s2dmain.html?http://www.fsb-shop.com/0000009527148a504/00000095260d6e580/000000952611d5823/000000976e0ef6e01.html

What I want you to look at are the pictures at the bottom. You can easily see the effect of Rewoquat: The five pictures at the bottom show a Parkinsonia from Sengenthal 1.) original condition as found, 2.) after 24h, 3.) after 48h and 4.) after 72h in Rewoquat.

Thomas

Edited April 28, 2010 by oilshale

[JimB88]

The surfactants used to remove marl or mudstones are quaternary ammonium surfactants, but they are not Benzalconium surfactants and belong to a slightly different class. They are amino-ethyl-Imidazolinium surfactants. Rewoquat W3690 for example is 1-Methyl-2-Noroleyl-3-Oleic-Aminoethyl-Imidazolinum-Methosulfate. Benzalconium surfactants won't work (at least the ones I tried didn't work).

Here is a link (sorry, the page is in German).

http://www.fsb-shop.com/assets/s2dmain.html?http://www.fsb-shop.com/0000009527148a504/00000095260d6e580/000000952611d5823/000000976e0ef6e01.html

What I want you to look at are the pictures at the bottom. You can easily see the effect of Rewoquat: The five pictures at the bottom show a Parkinsonia from Sengenthal 1.) original condition as found, 2.) after 24h, 3.) after 48h and 4.) after 72h in Rewoquat.

Thomas

Thanks for the info guys, Ill have to look around and see if I can find some thats affordable (I wonder if Lowes would have anything?)

[Wakaritai]

Thanks for the info guys, Ill have to look around and see if I can find some thats affordable (I wonder if Lowes would have anything?)

just be sure to use a full-face respirator (and nothing less). If that stuff will eat rock, it will have no trouble eating you as well. Eyes and lungs are especially susceptible. Most chemical damage to the face/eyes/lungs is caused by just fumes. I'm especially worried when chemicals contain ammonia-related compounds. I can't attest for that exact chemical, but I know of chemicals involving ammonia that readily react with tissue, especially that of the eyes and lungs (anything moist), to form a strong acid. One wiff or wisp of air can cause permanent severe damage to your eyes (including blindness) or any part of your respiration system. Very nasty stuff.

As long as you take the proper precautions, you'll be just fine.

[JimB88]

just be sure to use a full-face respirator (and nothing less). If that stuff will eat rock, it will have no trouble eating you as well. Eyes and lungs are especially susceptible. Most chemical damage to the face/eyes/lungs is caused by just fumes. I'm especially worried when chemicals contain ammonia-related compounds. I can't attest for that exact chemical, but I know of chemicals involving ammonia that readily react with tissue, especially that of the eyes and lungs (anything moist), to form a strong acid. One wiff or wisp of air can cause permanent severe damage to your eyes (including blindness) or any part of your respiration system. Very nasty stuff.

As long as you take the proper precautions, you'll be just fine.

Thanks for the advice, i happen to have a respirator.

[Harry Pristis]

The quat doesn't "eat" rock; it is a powerful surfactant that electro-chemically breaks down the bonds between particles. It is an additive to detergent products. I've seen no indication that fumes are a problem.

Rewoquat W3690 ('Oilshale's link) is manufactured by DEGUSSA and is available in the USA from:

Goldschmidt Chemical Corp.

914 East Randolph Road

Hopewell, VA 23860

phone 804/541-8658

(You may have to get the name of a local retailer from Goldschmidt. There are a number of formulations under "Rewoquat" so the "W3690" is important.)

I picked these preparation comments of the Internet:

"Putting my experiences with Rewoquat finally together I can say that the Pros for the use of Rewoquat are:

· It is inexpensive (about 5 Euro/ kg) and it can be reused many times. It just gets cloudier and cloudier each time. If there are too many particles in it, replace it with fresh Rewo.

· It is easy to handle, "preparation while you wait".

· It can be used on extremely detailed, fragile and very problematic fossils. You get very good results, and it leaves no preparation scratches/ marks.

· It is very suitable for cleaning micro-fossils.

· Very good results are received also in combination with other methods, e.g. air-brasive or air-chisels and Rewoquat.

"The negative aspects are:

· There is no knowledge about long-term effects; the article by LIERL was published in 1992 and the author has not seen any changes of the treated fossils since then [ten years]. (The method was mentioned before that in 1985 (Riegraf) and 1990 (Blank) where it was used successfully both times on microfossils from the posidonien-shale (lowerToarcium); also in combination with other methods, e.g. 1st treatment with hydrogen peroxide.

· There are ecological problems even so it is a fabric softener (but highly concentrated): it is forbidden [in the European Union] to put any Rewoquat into the water system. It has to go into the hazardous waste collection. Collect the 1st wash-water as well when using Rewo on a larger scale.

· Health and safety precautions you have to deal with.

· So far I could not find a consolidant which is not getting soft in Rewo after 4 treatments (due to the washing water) and so it needs to be put on again. An alternative should be found."

...................Symposium of Palaeontological Preparation and Conservation. (2002)