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Polishing agatized dinosaur bones


#1

Wow!

For days now I have been reading about this subject on agatized Dino
Bone. I found a source for alot of it and am trying to cut some. My
tools are very basic. I don’t have any high grit abrasives to work
with. Last night I tried to shine some of this gorgeous stuff and I
couldn’t get more than a waxy shine finish. My last grit used before
a Leather lap and some Orange-ish polish paste was 1200 grit diamond
lap. Like everything else, (like metal working) I am not formally
educated in the Lapidary field. Could some one give me some quick
hints to get that shine up higher (more closer to glass) with some
short cuts? Any tips are much appreciated.

Sincerely
Devin Startup


#2
Orange-ish polish paste 

That sounds like Cerium Oxide. I prefer to use Tin Oxide on a split
cowhide for dino bone polishing.

Rick Copeland
rockymountainwonders.com


#3

There are some materials in the Lapidary trade that just don’t care
to be polished the way we want them to be polished. Lapis Lazuli is
one of them. Dinosaur Bone is another one of those materials that
hate to play the way we wish them too. Because Dino Bone is composed
of calcite, trace chalcedony, calcium, etc, it has areas of differing
hardnesses. What this means to us is one area will polish with an
agent while the very same agent cuts another. Undercutting. Eggshell.
Pits. (If you or anyone else discovers a way to prevent this from
occurring without the use of impregnating agents, please let us
know.)

BTW, it sounds like you are using Red Rouge. Rouge is too aggressive
and it too easily can stain. Try cerium oxide on leather.

(And Now, tossing in my Two Cents on the related debate: Most of the
Dinosaur bone on the market is from the Moab, Utah area. This
material is not petrified or opalized. Nor is it psudomorphed. Not
sure of it’s origins entirely, but I do know this; There are examples
of petrified [Agatized] and opalized dinosaur bones in existence.
Chances are we will not be able to cut them unless found abroad.
Utah, and some other states, allow collection of vertebrate fossils
from private land, and private land only. All other domestic [US]
material is property of the federal government and is protected. Now
if they find suitable material elsewhere and can sell it, fine. My
point is the material we know and use comes from one small speck in
the map. Once another source emerges with differing characteristics
a new debate will be sparked on nomenclature. “Dinosaur Bone” sounds
fine to me.)

TL Goodwin
http://www.thepacifikimage.com


#4
That sounds like Cerium Oxide. I prefer to use Tin Oxide on a
split cowhide for dino bone polishing 

I thought there might be more on this today form our lapidaries. My
first thought on this post was the #1 most common mistake new cutters
make, is being in too much of a hurry. Every step must be complete in
polishing stones, and the harder the material is the more it matters.
Novices tend to grind and then go to 600 and sand until it looks
"pretty smooth", and move on. If your stone looks fogged, it could be
that another compound is better, as above. Look at the surface under
magnification - if you see fine, deep down scratches then you aren’t
spending enough time on the prep, and the next phase will not get rid
of it - every step must be complete. In which case backtrack a step
or two and spend some more time there. You don’t just sand down to
the scratches, you must sand THROUGH them. Maybe it’s that, maybe
it’s tooling and compound.

http://www.donivanandmaggiora.com


#5

I’ve prepared a response; I consider myself a lapidary among some
other things.

As I was typing a response one thing led to another resulting in
several pages so far.

As John points out:

if you see fine, deep down scratches then you aren't spending
enough time on the prep, and the next phase will not get rid of it -
every step must be complete. 

I just can’t give a simple easy answer, it’s a matter of steps. So, I
have work that people are paying me to do; but as time allows I’ll
complete my lapidary response.

KPK


#6
There are some materials in the Lapidary trade that just don't
care to be polished the way we want them to be polished. Lapis
Lazuli is one of them. 

Since you brought it up, what does one use to polish Lapis? I have
fair to middling success with Zam. But I’ve seen polished Lapis look
much better at shows. Is that stuff waxed or a sealer applied?

Rick Copeland
Silversmith and Lapidary Artisan
Rocky Mountain Wonders
Colorado Springs, Colorado
rockymountainwonders.com