Preparing a sea urchin

[Max-fossils]

Hi all,

 

First off, I am a real noob when it comes to prepping fossils... This is why I have a question for you, which I don't think would be too hard for you pros out there.

Some of you may have seen this sea urchin before; anyways I wanted to prep it, as I believe it will look quite nice after a good prep. There is just one problem though: the matrix is very hard (compared to what I'm used to). So how should I clear all this matrix?

The tools I have are very limited, but I can buy new things (as long as they are very cheap materials). I have: one long thin metal needle, one strong pointed needle, one strong small chisel, and one thing to blow the matrix away (sorry if I don't have the correct terms)... If needed I can post a picture of the tools.

Here is a picture of the fossil:

 

[gigantoraptor]

An air scribe is really good for prepping fossils. I don't know how much money you want to spend, but mine is the cheapest (good) one in the market I think. It's a HW1 from a dealer in Brussels (Belgium). I don't know if you have a compressor, but you need that too. If you don't have the tools or the money to buy the tools, maybe it's better to wait until you have, otherwise you'll regret it later.

 

Nice urchin indeed, where is it from?

 

 

[Max-fossils]

32 minutes ago, gigantoraptor said:

An air scribe is really good for prepping fossils. I don't know how much money you want to spend, but mine is the cheapest (good) one in the market I think. It's a HW1 from a dealer in Brussels (Belgium). I don't know if you have a compressor, but you need that too. If you don't have the tools or the money to buy the tools, maybe it's better to wait until you have, otherwise you'll regret it later.

 

Nice urchin indeed, where is it from?

 

 

Ok, thanks for the info! I'll see whether that air scribe is in my money range.

 

Thanks again! 

 

Max

[Ludwigia]

If you're willing to invest a good few hundred Euros, then air scribe with compressor would be the best. An air abrader to go along with that would be even better, but then you'd have to fork out another few hundred for that and a cabin. Otherwise you can try your luck with a dremel, or just take your chances with a few well-placed strikes on the matrix with a hammer and fine chisel and then scrubbing it afterwards under running water with a wire brush.

[abyssunder]

It will be difficult to prep it without  proper tools, as was suggested before. You should be very careful with this specimen, because the matrix is hard sandstone and the fossil tends to break along the plate sutures. Good luck in the prep!

[Max-fossils]

11 hours ago, Ludwigia said:

If you're willing to invest a good few hundred Euros, then air scribe with compressor would be the best. An air abrader to go along with that would be even better, but then you'd have to fork out another few hundred for that and a cabin. Otherwise you can try your luck with a dremel, or just take your chances with a few well-placed strikes on the matrix with a hammer and fine chisel and then scrubbing it afterwards under running water with a wire brush.

 

9 hours ago, abyssunder said:

It will be difficult to prep it without  proper tools, as was suggested before. You should be very careful with this specimen, because the matrix is hard sandstone and the fossil tends to break along the plate sutures. Good luck in the prep!

A few hundreds is indeed out of my money range

I'll put those tools on my wish list, and keep the fossil unprepped for now.

 

Thanks for all the help though!

 

Max

[Ludwigia]

1 minute ago, Max-fossils said:

and keep the fossil unprepped for now.

 

Max

 

Probably the wisest decision under the circumstances.

[Max-fossils]

Just now, Ludwigia said:

 

Probably the wisest decision under the circumstances.

What I thought too

[RJB]

Which way to prep that really depends on the rock?  I use to prep out a lot of echy's years ago.   The rock on them was extreamly 'sticky', meaning the rock is litterally glued onto the fossil and I did try my airscribe, but I had to wear away the rock with the side of the tip.  That just wasnt working.  A freind of mine used an air abrasive system on his ech's but that gave them a very wierd wavy pattern.  i bought a cheap little grinder tool adn with the right kind of tips, i was able to get some good specimens, but they had to be polished. 

 

RB

[siteseer]

RB,

 

Those look like the Dendraster specimens collectors used to find near San Francisco.  I haven't been there (somewhere off of Sloat, I heard) but saw some a local lapidary guy had.  He prepped them himself too, telling me you need to polish them because you can't find where the rock ends and the sand dollar begins.  He passed away some time ago - good guy.

 

Jess

[RJB]

Siteseer:   These do look almost exactly like the Dendraster excentricus, but these are known as Scuttilaster major.   The 'poop shoot' on these are on the dorsal side of the test and not the ventral like on the Dendraster.

 

RB

[Max-fossils]

On 5/16/2017 at 4:06 PM, RJB said:

Which way to prep that really depends on the rock?  I use to prep out a lot of echy's years ago.   The rock on them was extreamly 'sticky', meaning the rock is litterally glued onto the fossil and I did try my airscribe, but I had to wear away the rock with the side of the tip.  That just wasnt working.  A freind of mine used an air abrasive system on his ech's but that gave them a very wierd wavy pattern.  i bought a cheap little grinder tool adn with the right kind of tips, i was able to get some good specimens, but they had to be polished. 

 

RB

Ok, thank you! I don' think I'll polish them though, as (in my opinion) it kinda looks like some of the authenticity got taken away...