Jump to content
sneakyelf

What is the best substance for a false matrix for loose bones?

Recommended Posts

sneakyelf

What do preparers use to create a false matrix for fossil displays like this?  

Thanks! 

s-l1600.jpg

Share this post


Link to post
Share on other sites
Thecosmilia Trichitoma

I do not know of many instances where this is used. However, resins, plaster of paris sculpting clays and stone from the site where the fossil was found are all possible. The specimen in question seems to have some sort of plaster as the “matrix.” Usually fake matrix is put on to hide restoration in fossils or when a fossil is completely faked, either to be put in a museum setting or to be sold as a real fossil. From what I have seen, fossils are usually either kept in the original matrix with one side exposed, or completely removed and displayed as such. An exception to this might be the Messel fossil pit lagerstätte, where fossils are exposed on one side, covered in resin and then have the shale side removed. @oilshale may have more to say about this process.

Share this post


Link to post
Share on other sites
Ptychodus04

I can’t imagine wanting to do this, unless you have no other way of displaying the specimen. I agree with the plaster suggestion. You can stain it to approximate the host matrix.

 

I would much rather use an armature mount if possible though.

Share this post


Link to post
Share on other sites
Harry Pristis

An example from Messel:

 

 

fish messel amia.jpg

Share this post


Link to post
Share on other sites
Pemphix

Transfer Prep is needed, cause the Messel sediment bearing the fossils contains more than 40% of water. If the sediment getting dry, nothing more than some splinters and chunks are left. So you need to transfer the fossil onto a matrix which is more durable:

 

https://www.senckenberg.de/de/institute/senckenberg-gesellschaft-fuer-naturforschung-frankfurt-main/abt-messelforschung-und-mammalogie/ueber-den-tod-hinaus-entdeckung-und-praeparation-eines-fossils-aus-der-grube-messel/

 

https://www.wissenschaft.de/erde-klima/einblick-in-die-fossilien-praeparation/

 

P.S.: correct naming of the species is Cyclurus (former "Amia") kehreri (ANDREAE 1893). Age of Messel has been dated to 48 million years.

Share this post


Link to post
Share on other sites
oilshale
Posted (edited)

Before the transfer method was used, Messel fossils were either dried very slowly (over several years - this often resulted in shrinkage cracks anyway) or stored permanently under glycerol or ethylene glycol. Glycerol and ethylene glycol both have high boiling points (do not evaporate), are miscible with water, and have slowly replaced the water in the oil shale. This method was also used in the conservation of the Vasa, a Swedish warship from the 17th-century https://en.wikipedia.org/wiki/Vasa_(ship). Another preparation method was to prepare the fossil freely on one side, then embed it in paraffin wax and remove the remaining substrate (also a kind of transfer preparation).

I have seen a few times fossils from the Cretaceous (Niobrara Formation) of Kansas that were embedded in gypsum, this also seems to be common there, but normally I would only replace the matrix if absolutely necessary.


Quote from  https://fineart.ha.com/itm/fossils/fish/ferocious-bulldog-fossil-fish-skeletonxiphanctinus-audaxcretaceousniobrara/a/5435-72085.s

"Given the instability of the matrix in which these fossils are found, it is necessary to collect them using the painstaking plaster jacket method, whereby the bones are cleaned in the field, a frame is constructed around the fossil, and then finished with plaster. After the plaster has set, the slab is dug under and loosened, then carefully turned over. This exposes the underside of the fossil which is then painstakingly prepared in the laboratory for exhibit."

Edited by oilshale

Share this post


Link to post
Share on other sites
Troodon

Many of the Niobrara specimens I've seen at the Tucson show over the years all were prepared using the plaster jacket method.  A dealer at these shows who lives in Kansas explained the exhausting process to collect large fish.  Not like collecting in other places.  

 

 

 

Share this post


Link to post
Share on other sites
sneakyelf

Thanks everyone.

I also received a message offline about "Durhams Rock Hard Putty" to create a background matrix that can be textured and painted. I have a handful of plant fossils I found and I thought they would look cool if they were all sitting together in a "matrix" so they could be hung on wall.  

Share this post


Link to post
Share on other sites
jpc

try it first with any less cool specimens you might have, in case it doesn't turn out as you hope.

Share this post


Link to post
Share on other sites
LabRatKing

I was a fan of a product called  Thunder Stone, however, it looks like it is not made any more.

 

truth is good old plaster of paris amended with acrylic fortifier and things like sand work exceedingly well.

 

Some high dollar reproduction firms use a "wood cellulose medium" whish is basically the same thing but with cellulose powder mixed in as a binder and weight reducer.

 

Currently, a good one is"Castrite" which is an ultra fine specilized plaser. I have worked with it in the past, and it is an very strong, lightweight media. It results in an almost fired-ceramic like solid. It also can be painted, tinted, and mixed with aggregates for that "straight outta the quarry look".

 

The advantage to the gypsum based products is that they can easily be removed and or repaired if you decide the actual fossil needs to be free again.

 

As for coloring and pigments, this takes some skill and practice to achieve the look you want. When I get home from the office, I will post pictures of a 100% artificial "stone" hearth I built for my living room (and yes, there are even faux-sils worked into the end result.

 

However, no matter the route you choose, as @jpc stated, practice first before moving on to the good stuff. Something as simple as 10 bucks worth of PoP from the hardware store, a cardboad box, and some sticks and chicken bones will help you develop your technique.

Share this post


Link to post
Share on other sites
jpc

Truth is, if I had been doing the mosasaur shown above, I would use a shadow box with thick sturdy foam in it.  Carve a hole for each bone in the foam, then line the whole thing with a nice monochromatic cloth and call it good.  If it is to stay horizontal, this would work well.  If you want o make it vertically mounted, you would have to cut the foam so that it holds the bones in, or include some other clever anchors.  Something lie a Riker Mount on steroids.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Recently Browsing   0 members

    No registered users viewing this page.

×