rockhound97058
freely admits to licking rocks
Thundereggs - Oregons Official State Rock!
Member since January 2006
Posts: 760
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Post by rockhound97058 on Apr 19, 2009 23:50:43 GMT -5
In regards to my other post I mentioned I had a claim in Central Oregon which produced Opal Filled Thundereggs. Many of them are jelly opal filled, however I also get Precious opal and contra luz opals. My digital camera has a very hard time picking up the "play of color" but here's a few samples for you.
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Post by akansan on Apr 20, 2009 12:58:12 GMT -5
Very nice! How stable is the opal?
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Post by Michael John on Apr 20, 2009 16:48:46 GMT -5
Mmmmmmm, yummy!
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MikeS
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Post by MikeS on Apr 21, 2009 17:18:32 GMT -5
very cool!
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Post by Bejewelme on Apr 22, 2009 6:20:24 GMT -5
Thanks for posting these, I saw some of these on ebay, very pricey!! I too am curious if they are stable, the colors are amazing!!! Amber
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rockhound97058
freely admits to licking rocks
Thundereggs - Oregons Official State Rock!
Member since January 2006
Posts: 760
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Post by rockhound97058 on Apr 24, 2009 0:44:32 GMT -5
Afraid my material is very unstable. I do have a couple pieces which seem to be crazed to it's maximum which left a very nice window of stable material. I tried to have triplets cut, but never could find a person interested in doing so. So basically it's just specimen material ~ looks pretty in the jar. I'm curious about the one you seen on ebay. If it was fairly recent it wasn't me..... However there was a fellow several years ago who had some eggs from Central Oregon which looked very close to my material. There's also Opal Butte material which has precious opal as well. In fact the other day I cut a 8" Opal Butte Thunderegg with fantastic jelly opal! I have several more large eggs to cut as well. Also I cannot be certain it wasn't my material as people claim jump and dig at will anyways.... I try to keep it low profile due to the opals, but hey I can't babysit it year round
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Post by Tweetiepy on Apr 24, 2009 12:15:37 GMT -5
What do you mean by unstable?
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rallyrocks
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Post by rallyrocks on Apr 24, 2009 12:41:22 GMT -5
Tweetie- when people talk about the stability of opal they are usually talking about opals tendency to crack or "craze", from shock or either from drying out or else absorbing too much water, and unfortunately, with few exceptions, most North American opal suffers from instability of this kind to some degree, which make them generally unsuitable for cutting or setting- or even leaving around outside of a sealed jar full of water.
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SteveHolmes
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Member since July 2009
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Post by SteveHolmes on Apr 24, 2009 19:07:06 GMT -5
Those are Sweet Jason. Do you want to hire a year-round babysitter??? I'm Available! Steve
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rockhound97058
freely admits to licking rocks
Thundereggs - Oregons Official State Rock!
Member since January 2006
Posts: 760
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Post by rockhound97058 on Apr 25, 2009 0:19:02 GMT -5
Exactly... Opals contains various percents of water. Upwards of 20% if I remember correctly. In fact the "fire" or "play of color" you see in the stone is actually microscopic water sphericals trapped within the stone. These sphere bend white light into the spectrum of colors such as you see a rainbow during a rain shower. My opals in general are dug about 6000 ft elevation and I have snow for most months of the year, during the hottest part of summer I can dig down a couple feet and still hit cool, moist soil.... So with the conditions my opals are in... Once I dig them and expose them to the normal air... in a sense they are drying out or dehydrating, this creates stress on the stone and creates cracks and craze lines. There has been many, many people who have theories, or great idea's on how to stablize opals, but I have yet to see something that actually works. I'd love to find something and be able to offer the stones as jewelry grade as some could make outstanding stones. When I first started mining this claim 8 years ago some of my first pieces of opal was shipped to the east coast to a large opal company and they appraised a couple pieces upwards of $1500 per carat. IF it was completely stable to cut solid cabs... It's not stable - so it made a nice specimen in the jar of water. Hmmm Steve, a year round babysitter.... Might be a good idea, but it'll get cold for ya from about November to June LOL. Maybe there's some trick to the stability if it's frozen when we dig :cheesy:
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Post by bobby1 on Apr 25, 2009 11:15:42 GMT -5
Does any have stable thin layers? I can try to make some triplets for you if you want. I've done a lot of Spencer Opal triplets, but the material is definitely stable. It comes in very brilliant thin layers that can only be done as triplets. I can post some photos if you want. Bob
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highplainsdrifter
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Post by highplainsdrifter on Apr 26, 2009 8:31:02 GMT -5
I wonder if anyone has tried stabilizing opal with a thin hydrophobic coating of silane-based polymer?? Of course you'd have to coat again after cutting it. The water may still be able to diffuse out..just a thought
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mossyrockhound
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Post by mossyrockhound on Apr 26, 2009 13:06:01 GMT -5
Very nice opals! Too bad about the stability problem. I was wondering if it could be stablilized by very slowly drying out to the same water content that the Australian opals have (which seem to be fairly stable). I believe opal is amorphous though, so I don't know how the water could get out. Maybe this drying could be done over a year or so under controlled conditions. At $1500 per carat, some lab testing could really pay off!
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jcinpc
has rocks in the head
Member since April 2009
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Post by jcinpc on Apr 26, 2009 21:06:43 GMT -5
I wonder if you could do like I do for my bone artifacts I preserve. I use duco and acetone to preserve them. The acetone draws out the water and the duco bonds it.
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Post by Noosh9057 on Apr 27, 2009 8:18:00 GMT -5
Very nice.
Roger
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rockhound97058
freely admits to licking rocks
Thundereggs - Oregons Official State Rock!
Member since January 2006
Posts: 760
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Post by rockhound97058 on Apr 28, 2009 0:22:36 GMT -5
Like I said before... I've tried many options and have yet to find anything that works on making the opal any more stable than before. I've even had a fellow who worked as a scientist at the Hanford Nuclear Plant try to work with it with no luck. His theory was to place the opal in a vacuum chamber and pull a very hard suction.... This in turn will pull the moisture from the opal, and then inject a polymer or other substance to stabilize the opal.... To a point it did work as the opal lost 1/3 it's weight, however when the vacuum pulled the moisture it froze it to the surface of the opal causing a few fractures.
"Bob" - I appreciate the offer to cut triplets.....I don't have much opal right not to part with.....however let me know what the minimum is - you require to work with. The opal from my claim comes in Thunderegg form, and I have not seen any "seam" type material such as Spencer. I have several Spencer specimens and know exactly what your talking about. Also I'm unsure if any of my specimens have thin "stable" layers as well. I know I do have a couple pieces which have stable windows, or at least area's they did not crack.... however they are very small pieces. Sometime down the line, it would be fun to see if any of my contra luz would craze down to usable pieces and cut some small faceted stones. But for now, their pretty and look cool in the jar.... It's cool to own a spot which produces a rare stone in the state of Oregon.
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lapidarious
off to a rocking start
Member since April 2009
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Post by lapidarious on Apr 28, 2009 16:28:06 GMT -5
Yeah, Oregon opal is world class in its play of color, stability not withstanding. Opals structure is composed of tiny spheres of silica gel of various sizes. If these spheres form in the same size and line up as like marbles in a shoebox, they will act as a prism and reflect light in a color that depends upon the size of the sphere. Different colors come from different groups of different like sized spheres If the spheres are randomly sized it results in common opal, and is the bulk of opals structure. But as a box full of random sized marbles is hard to stack, on a microscopic scale this results in various sized spaces between the spheres. this is the space that is full of physical water. As that space dries out those odd sized spaces create stress within the opal and that results in crazing. Very true that they have not made a way to stabilize opal, and while water loss is a very high reason for the stress to result in crazing it isnt the only factor. Its ironic some of the most beautiful items in the gem kingdom are so unpredictable as to their longevity.
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