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 Post subject: Re: Fossils that are used as Gems
PostPosted: Thu Oct 06, 2011 12:40 am 
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There's another fossil material that's gaining wider attention as a gem: the opal-like ammonite shell from Canada and the northern U.S. that's trade-named Ammolite. It gets its play of color effect from unusual microstructure of the mineral aragonite. Here are two examples from several in my inventory:


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 Post subject: Re: Fossils that are used as Gems
PostPosted: Thu Oct 06, 2011 2:20 am 
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Very nice, Rick! I haven't cut any ammolite yet, but I have been searching for some good "oak leaf" ammonite to cut. I've seen incredible cabs cut from that stuff. That coral is magnificent! It has a different look than the Indonesian material. I like it. Your pet wood might be from the same area as the Herringbone wood, no doubt! The Sycamore I posted below the Herringbone is from the Hell's Canyon area.

Here's a dino bone cab I have in the works
Image


And we cannot forget fossilized horn coral from Utah,
Image

fossilized palm wood from Texas
Image

And these little crinoid fossils in marble from China
Image



Let's keep this thread going!

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 Post subject: Re: Fossils that are used as Gems
PostPosted: Thu Oct 06, 2011 3:26 am 
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odors?
ehmmm...sorry...what about coprolite then ?
:)


Stonebender wrote:
VERY true Rick, it does give off a very distinct odor. No matter how well agatized it is too. I think that's one of the things that attracts me to dino bone- it actually once being a living creature. It gives you kind of a mushy, special connection with history. Not to mention it can be downright gorgeous!


Barbra Voltaire wrote:
Oh, no worries....I thought that "Fossils used as Gems" would be a real interesting topic on it's own.....
If you posted an opalized clam shell pseudo-morph on the opal thread it would have been a tough decision, but the dinosaur bone is now "born free".


Well, in that case, I have plenty of pictures to share in this topic!! It really is a pretty good idea for it's own topic. Good idea!

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 Post subject: Re: Fossils that are used as Gems
PostPosted: Thu Oct 06, 2011 8:34 am 
Can you bring out more detail under the microscope, Rick, or does the symmetry simply disintegrate?


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 Post subject: Re: Fossils that are used as Gems
PostPosted: Thu Oct 06, 2011 11:14 am 
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Kerensky wrote:
Can you bring out more detail under the microscope, Rick, or does the symmetry simply disintegrate?

I'm not sure which stone you're referring to Owen. In any event I'm not a microscopist although I'm sure additional detail in dinosaur bone would be revealed with magnification.

One thing I've noticed is some considerable variation in bone cell sizes. Most of my pieces exhibit cells in the approx. 1 to 1.5 mm. size but I have one lovely red slab that requires 10X magnification to make out the cell structure. I'm not clear why that should be unless such size variation existed in the bones of the actual living creature.

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 Post subject: Re: Fossils that are used as Gems
PostPosted: Thu Oct 06, 2011 11:21 am 
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studiogem wrote:
odors?
ehmmm...sorry...what about coprolite then ?
:)


I knew this comment was coming. Why don't you experiment with that and give us a report? I've never actually cut any coprolitic material. :roll:

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 Post subject: Re: Fossils that are used as Gems
PostPosted: Thu Oct 06, 2011 11:23 am 
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Thats really interesting stuff. It takes a nice polish too! I wanted to go to denver so bad this year but couldnt. I am jealous :-P.

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 Post subject: Re: Fossils that are used as Gems
PostPosted: Thu Oct 06, 2011 12:01 pm 
ROM wrote:
Kerensky wrote:
Can you bring out more detail under the microscope, Rick, or does the symmetry simply disintegrate?

I'm not sure which stone you're referring to Owen. In any event I'm not a microscopist although I'm sure additional detail in dinosaur bone would be revealed with magnification.

One thing I've noticed is some considerable variation in bone cell sizes. Most of my pieces exhibit cells in the approx. 1 to 1.5 mm. size but I have one lovely red slab that requires 10X magnification to make out the cell structure. I'm not clear why that should be unless such size variation existed in the bones of the actual living creature.


Sorry, I was actually thinking about the symmetry in the coral structure.

With regard to the dinosaur bone, am I in trouble too over the word 'cell'? My understanding is that a 'cell' in the biological sense are microscopically small and are the smallest arrangement of complex chemical compounds to capable of independent life (as in single-celled organisms). I guess, you must be talking about the relatively huge and irregularly spaced and shaped voids in bone that make bone light and provide 'factory floor space' for living cells that repair, replace, fight infection etc?


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 Post subject: Re: Fossils that are used as Gems
PostPosted: Thu Oct 06, 2011 12:48 pm 
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Kerensky wrote:
I guess, you must be talking about the relatively huge and irregularly spaced and shaped voids in bone that make bone light and provide 'factory floor space' for living cells that repair, replace, fight infection etc?

Yes, I'm sure you're right about that. I fell unthinkingly into the popular jargon one hears around U.S. gem shows, etc. Those voids would be the the natural places to be filled by silica during fossilization. And that probably answers my earlier question about size differences. The size of the voids would vary depending on bone density.

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 Post subject: Re: Fossils that are used as Gems
PostPosted: Thu Oct 06, 2011 1:07 pm 
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"Fossils that are used as Gems" indeed is an interesting topic. It will help to share the knowledge of fossils gems.

HUK


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File comment: fossilized shell / jasper, Variety of Quartz
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File comment: fossilized shell / jasper, Variety of Quartz
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File comment: fossilized shell / jasper, Variety of Quartz
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 Post subject: Re: Fossils that are used as Gems
PostPosted: Thu Oct 06, 2011 2:00 pm 
ROM wrote:
.... Those voids would be the the natural places to be filled by silica during fossilization. And that probably answers my earlier question about size differences. The size of the voids would vary depending on bone density.


As an enthusiastic hunter for over 50 years, I've looked at a wide variety of smashed bones and the bone density seems to vary mainly according to the stresses that the bone must bear. Within a single species, skulls (e.g.) are much more porous than shin bones :) I understand too that loss of bone density is one hazard of spaceflights lasting more than a matter of days as, when the body is weightless, the rate of bone replacement slows markedly. Though most whales are massively larger then (say) deer, the density of their spinal vertabrae (almost like pumice) is much lower than that of deer. Probably, this is because for whales the downwards force of gravity is pretty closely balanced by the upwards force of their buoyancy in water.

It would be interesting to know if this observation might help the separation of the bones of land-living dinosaurs from the like bones of those which were water-living, on the basis of relative bone porosity in specimens of approximately the same mass 8)


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 Post subject: Re: Fossils that are used as Gems
PostPosted: Thu Oct 06, 2011 2:28 pm 
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I think "cell" isn't necessarily referring to the literal biological sense. Think more like a 'singular, closed-off space' sense of the word- like a prison cell, or photo cell, referring to the irregularly shaped spaces of color with boundaries of a thin "webbing".

Like these definitions for the word 'cell':

1. any of various small compartments or bounded areas forming part of a whole.

2. a small group acting as a unit within a larger organization: a local cell of the Communist party.


I don't know if that was an issue worth clearing up, or if you were just posing a rhetoric statement, Kerensky.

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 Post subject: Re: Fossils that are used as Gems
PostPosted: Thu Oct 06, 2011 4:04 pm 
Cutting to the chase, I'd be interested learn whether a differing size of voids in dino bones of similar function can help determine whether or not the dino was aquatic.

As to the organisation of covert political organisations under centralised command and control, I'll go elsewhere to discuss that :wink:


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 Post subject: Re: Fossils that are used as Gems
PostPosted: Thu Oct 06, 2011 4:21 pm 
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^ nice question! Would that matter with the cells in bones if its aquatic? I would have thought it would only matter of it was a flying dino (more air in bones = less weight). But I know NOTHING about animal biology, just find it interesting.

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 Post subject: Re: Fossils that are used as Gems
PostPosted: Thu Oct 06, 2011 4:27 pm 
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Stonebender wrote:
I think "cell" isn't necessarily referring to the literal biological sense.

I'd agree with you if we weren't discussing a fossilized biological material. In my mind, at least, the use of the word "cell" in relation to dinosaur bone connotes a biological cell, not a "guest room" at San Quentin.

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