Exclusive interview: Fossil preparation

Every serious collector of fossils will at some point have found herself either trying to remove a fossil from its matrix, repair a broken fossil, stabilize, restore, or polish a specimen to improve its appearance.

What did it take to prepare this beauty?

What did it take to prepare this beauty?

When getting help from one of the very most expert fossil preparator labs on the planet – White River Preparium – to prepare a gorgeous 3.5 inch Tyrannosaurus Rex tooth, The Fossil Collector was extremely lucky to also have gleaned a rare glimpse into the workings of the fossil preparator trade. Thank you so very much Sandy and Ed for your generosity in granting us this exclusive interview!

Softening the matrix

1. Softening the matrix

Sandy, how did your passion for fossils start?

It all started in Scenic, South Dakota at age 10, on a picnic with my parents. My mother and I were cooling our feet in the creek, I looked down and saw my first Oreodont molar.






Scraping off the matrix and glue

2. Scraping off the matrix and glue

Can you describing how fossil preparing trade came to be?

I’m not sure about when the trade started or why? Guessing, they needed to hold fossils together. Collecting them, they had no choice but to figure out what worked in preserving them. The techniques for preservation have evolved through the years, for the better. As the industry also evolved, many techniques were tried. Some worked while others failed. Now there are glues made specially for the trade, that seem to be able to hold up through time.

3. Air braiding with bicrab and final cleaning

What’s the fossil preparator ‘industry’ landscape like?

There are many well-qualified and professional preparators out there. Most prepare for themselves, some will do outside preparation work for others. They may work on one type of species or like myself, work on many different species. It depends on the individual.


How did you come into this profession?

I owe a lot to my husband, Ed. I had filled out an application for a job at the Black Hills Institute in Hill City, South Dakota, (where there) never seemed to be an opening. It wasn’t until my husband started working on the roof at BHI, I would stop by after work and wait for Ed to finish his work day. One day, I asked if there was something they would allow me to work on? They handed me an ice cream bucket three-quarter full of Oreodont single teeth, they taught me how to use an air scribe to clean the harder matrix from the teeth, air braiding to clean the rest of the residue. After cleaning, I was asked to separate them by species.


4. Crack-filling

As days, weeks, months went by waiting for Ed, I started to learn the differences of the Oligocene mammals. I also found I so enjoyed working with Oligocene material. A job opening came 1986, starting from the bottom. Not long after, they offered me (an opportunity) to work on lower-end items, such as partial Oligocene mammal skulls, single side lowers, items worth between US$1.00 up to US$30.00. I figured I must have done well enough, since they soon started me on nicer skulls and turtles. I worked at BHI for four and half years, until I had an opportunity to work with someone else in the business. I owe everything to Pete Larson, Bob Farrar, Neal Larson, and several other employs at The Black Hills Institute. I wouldn’t have had a fossil preparation business if not for them.

Also I owe a lot to Leon Thesien, owner of Custom Paleo. I worked with him and his wife at the time, Diana. Leon taught me just as much as the Larsons had, so much so, it gave me the confidence to strike out on my own after two years. However, to do that, I needed to know I’d have enough work to get started. Enter Allen Graffham, owner of Geological Enterprises, known as the Grandfather of Commercial Fossils, though he wasn’t the first in that business. He had boxes and plaster jackets that needed to be prepped. Now I had the work, but needed tools and a place. My parents offered to loan us US$10,000.00 to build a 400 square foot addition on to the back of our house and enough left over to purchase the tools needed.

Sanding restoration

5. Sanding restoration

Thus, I started my business, White River Preparium in 1993. The only material I had was Oligocene to work on. Allen Graffham and Leon Thesien kept me busy for a few years, after the Oligocene (jobs) started to dwindle down, the years were tough here and there. When people would call with other items to have prepared, such as dinosaur teeth, bones, trilobites, ammonites, scaphites, if I hadn’t worked on them before, I’d tell them such, but would love to try? Besides I wanted to branch out and I’m glad I did.

My husband, Ed was still working at BHI for another seven years after my starting the business, as their carpenter, photographer, and all-around handyman. After 12 years at BHI, Ed decided to work from home in 2000. Business was moving along, our name was getting known. It took several years to build the business, it didn’t happen overnight. In this business, there aren’t too many female-owned fossil preparator businesses. That I know of! I know many talented men and women in the industry, not too many females that own their business. As the years came and went, we have been getting busier then ever. I have been working on fossils for 30 years and in business for 23 years….still going strong.

Restored and ready for painting

6. Restored and ready for painting

Would you encourage others to enter this profession?

If you have the patience and talent, just about anyone can learn to prepare fossils. It is however better to learn the right way to prepare, than the wrong. Some learn the wrong way, it can be very hard to un-teach them. If you can, find the best teacher out there!


What’s the fossil preparation process like?

First stage is to glue any cracks, specially enamel on teeth. Most soft matrix can be scraped off by knifing. Next is to air-brade, with the chosen abrasive used, helps to get in the smallest of areas and gives a clean surface. Once clean, epoxying the cracks and using epoxy for the smaller restoration, which is what was used on the Rex tooth tip I restored for you. Making of the shape and serrations is done while the epoxy is still curing and soft. After epoxy is hard, some sanding may be required to smooth the edges where the enamel and epoxy meet. It helps to smooth all the restoration. At this point it’s ready for painting, I use acrylic latex craft paint. And many different colors! When the painting is complete, I apply a thin layer of wax over the enamel part of the rex tooth.

Close up before painting

7. Close up before painting

Are there any handling instructions for prepped fossils?

Although it is fragile, it can be handled…but carefully. Paint and wax will be seen if scratched.



Can you recommend any resources that are useful to help achieve morphological accuracy?

I do use copies of hand-drawn illustrations of all the Oligocene fossils found in South Dakota. They were a gift from Leon Thesien and BHI when I started the business. However, after doing as many Oreodonts, turtles, and other more common skulls as we have, you just know what they look like after preparing hundreds of them. I do refer to the drawings for the less commonly-found specimens. Most dinosaur teeth and other fossils, you can look at the piece, it will show you what is needed, how to shape it, bevel the edges. It does help to have an eye for what it should or will look like when finished. We also seek help from BHI when we’re stumped on something. Or I might Google a picture if we have a question on where a bone should be positioned. Other than that, it does help to know ahead of time where the cheeks, teeth, and other fragile bones on the skull are, before beginning the cleaning of it. Of course, not all fossils are articulated, things can be shifted or not where they should be. It can be a lot of work to assemble a disarticulated skull. Like a puzzle at times, but I am one who has loved puzzles since a child. I’m in heaven placing pieces together, creating a finished specimen the client would be proud to show. Or, having an Oligocene block here with a skull and skeleton. Air-brading to expose the bones is still a thrill. You never know what might be discovered, such as rodent bite marks or injuries. I have seen many of both through the years, and find it fascinating every single time.

Painting the restoration

8. Painting the restoration

What should clients look for when deciding to work with a fossil preparator?

Best to ask other fossil friends that may have had work done before. The fossil world is small, most everyone knows one another or has heard about them. If working with someone new you haven’t yet heard of, ask for pictures of their work? If they’re proud of their work, they will be more than happy to show it! All preparator’s have different techniques and styles. Some good, some not so good. See if their work is what you find pleasing to the eye. I’ve had quite a few pieces in the lab, work done by someone else, here to be redone. At times it’s harder to undo others work, than starting from scratch. I’ve never advertised, it’s all been by word-of-mouth.

In your experience how does the value of different fossils change after preparation, and in what situations?

There are many that sell unprepared fossils, giving someone else a chance to try their hand at it or perhaps make a little money. Not all fossils are worth a great deal of time, if any. However, you might get one of those special fossils worth spending the time to have prepared. Like a nice sabertooth cat! They are highly sought after, depending on how easy it is to clean. What we call a free-mount (free of all matrix) is worth spending time. It depends on so many factors; are the teeth in good condition, how much is missing? The amount missing will mean more restoration and more cost to restore. You might purchase a cat for hundreds, that once prepared and prepared well, may bring thousands. However, you might have to invest a US$1,000.00 to US$1,500.00 in prep. Including the purchase of the unprepared skull, one can easily sell it for double, if not triple the costs you have in it. Some are worth the cost to have prepped and others just aren’t. If collectors or buyers are having their pieces prepared, the preparator should suggest options, how much work should be done. It’s best to work with someone in the business, with a few years under their belt who can better advise you.

Finished tooth!

9. Finished tooth!

Do you collect fossils yourselves and what is your collecting philosophy? What are some of your most prized specimens?

Ed and I did have a place to collect Oligocene material. We collected for four years, but after the business bloomed, we found we hadn’t the time. Ed once found a really nice complete Dinictis sabertooth cat skull, although the majority of our finds ended up being low-end pieces. I believe if no one is there to collect the fossils, they will fly away with the wind and the rains, never to be seen again. If it’s found and someone can make a little pocket change… I see nothing wrong in that at all. As long as it’s collected legally.

What advice do you have for anyone keen to learn how to restore fossils, either for their own collection or as a trade?

A tough question to answer, it depends whether they have had any experience in preparing? If you can find someone to teach you the trade, make sure it’s a preparator that knows what they’re doing and knows the correct way. It does help to have artistic skills, I have found artistic people learn quicker. If you feel confident, give it try! If not, please leave it to the professionals.

About chuyeeming

Just another passionate collector of fossils
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2 Responses to Exclusive interview: Fossil preparation

  1. I just finished working on an Oreodont skull that came to me in the mail. It turned out very nice! It was fully prepped, but the piece was severely damaged by the USPS. Chimpanzees could do better at delivery than the USPS in my opinion!

    Very interesting article! 🙂

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