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 Post subject: Re: Ethiopian Opal Agony and Ecstasy
PostPosted: Mon Sep 12, 2011 9:32 am 
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Which is the reason for my concern :)

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 Post subject: Re: Ethiopian Opal Agony and Ecstasy
PostPosted: Mon Sep 12, 2011 8:22 pm 
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Sounds like this Ethiopian stuff is not very good quality so I think I'll stick to the Lightening Ridge Black or Cooper Pedy white. Never had a problem with them as long as I cut away the sandstone rubbish, potch, sand-grains, sand islands, cracks, white milky clouds and any other flaw. But I don't like using epoxies or super-glues on them and therefore avoid using acetone and the like. To me dunking an expensive piece of opal into acetone is a sin :evil:


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 Post subject: Re: Ethiopian Opal Agony and Ecstasy
PostPosted: Mon Sep 12, 2011 9:43 pm 
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Gearloose wrote:
I do not know about his particular species of opal but at first glance would be concerned about damaging te color.
The RI of water in the opal structure is 1. If the water were repelaced with something with an RI closer to silica, some color play could be lost.


I don't know the opal optics but .... are you sure? Isn't water ~1.3 RI or so? I figure epoxy and alcohol to be maybe 1.5-1.7.

I'd love to hear this explained.

Anyhow, I did treat one finished faceted stone today. It was very slightly more attractive than it was totally dry and not nearly as nice as it was water wet.


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 Post subject: Re: Ethiopian Opal Agony and Ecstasy
PostPosted: Mon Sep 12, 2011 9:58 pm 
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gondwana wrote:
Sounds like this Ethiopian stuff is not very good quality so I think I'll stick to the Lightening Ridge Black or Cooper Pedy white. Never had a problem with them as long as I cut away the sandstone rubbish, potch, sand-grains, sand islands, cracks, white milky clouds and any other flaw. But I don't like using epoxies or super-glues on them and therefore avoid using acetone and the like. To me dunking an expensive piece of opal into acetone is a sin :evil:


Let me rephrase this and see what you think.

sarc
You can't put Lightning Ridge Black or Cooper Pedy white in acetone? Sounds like this Australian stuff is not very good quality, so I think I'll stick with Welo. Never had a problem with them as long as I cut away the sandstone rubbish, potch, sand-grains, sand islands, cracks, white milky clouds and any other flaw. But I don't like using waxes on them and therefore avoid using alcohol and the like. To me storing an expensive piece of opal with some water is a sin.
/sarc

Water, alcohol and acetone are three examples of solvents. Welo is hydrophane. Alcohol and acetone can work as drying agents. It actually is pretty amazing that welo can handle rapid changes in hydration without damage. I will continue to recommend using acetone with Welo as it cuts the drying time from 2 weeks to a day or 2 (dries and then it rehydrates to room humidity).

Next time, I want to try some John Church's dried Virgin Valley... When I can afford it.

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 Post subject: Re: Ethiopian Opal Agony and Ecstasy
PostPosted: Tue Sep 13, 2011 1:14 am 
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Dear Mr Ellis
If you're in such an urgent hurry to dry your opals I recommend you throw them in the laundry drier overnight. That would serve the double purpose of sorting the cracks and flaws as well as extracting the water plus you'll end up with a lot more than what you started with!

Skin is composed of water but I wouldn't recommend drying your skin with acetone! Though some people will try anything.


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 Post subject: Re: Ethiopian Opal Agony and Ecstasy
PostPosted: Tue Sep 13, 2011 3:25 am 
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acetone.... sounds like a great way to speed up the dehydrating of your beef jerky.
:mrgreen:
maybe this should be declared on sale as technically it is a treatment,you are force de-hydrating using chemicals in a process to achieve your results on a porous material.Opal is hygroscopic therefore any process affecting this should be declared as a treatment.The end result may be the same but you are obtaining it by un-natural process.

I am not a fan of any treatments on any gem and can barelyabide heating.

My 2c


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 Post subject: Re: Ethiopian Opal Agony and Ecstasy
PostPosted: Tue Sep 13, 2011 11:29 am 
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lightspeed wrote:
acetone.... sounds like a great way to speed up the dehydrating of your beef jerky.
:mrgreen:
maybe this should be declared on sale as technically it is a treatment,you are force de-hydrating using chemicals in a process to achieve your results on a porous material.Opal is hygroscopic therefore any process affecting this should be declared as a treatment.The end result may be the same but you are obtaining it by un-natural process.

I am not a fan of any treatments on any gem and can barelyabide heating.

My 2c

Cutting is a "treatment." You are hydrating it while using water for cooling/cutting and you are hitting it with WD-40 or Dr. Iggy's Snake Oil. Guess you need to count those too. The acetone helps remove the WD-40 too, which clearly is absorbed while cutting. You must be careful on keeping your laps clean as it will migrate swarf into the stone too but usually starts scratching like heck before you get there. The pores are huge and will migrate about anything and as noted, even dyes.

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 Post subject: Re: Ethiopian Opal Agony and Ecstasy
PostPosted: Wed Sep 14, 2011 12:06 am 
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Cutting opal and ending a human life is not a comparison ,not even the same ballpark.I believe that topic is covered by various other forums and am sure it has no part in gemology or lapidary arts.
The use of a cooling agent or lubricant should not have anything to do with effecting the internal makeup of a given gem (common exceptions to this are Ruby ,Emerald where oiling is a commercial treatment) as the intended purpose for the application of these chemicals(yes water is a naturally occuring chemical) is not for effecting a gemstones internal makeup but is an external application for where the gem is in contact with another surface for the purpose of cutting forming or polishing.I myself used refined Kero to cut as a lubricant now do not,the reason for this was the absorbtion into emerald(think of surface pressure between lap,lube and stone) while cutting,you are inadvertantly treating the stone with oil even though not by intention and the use of which was for another purpose.My conscience will not allow me to do this,and to sell as an untreated stone just because it wasnt for the specific intention of affecting the gems internals and appearance.
The use of a non natural and refined chemical and the soaking of the gem in it is for the singular purpose of effecting the stones appearance by water/oil absorbtion into a liquid that will evaporate easily.
I am not against dehydrating your opal but the use of immersion in a refined chemical denotes treatment ,and in the case of a liquid,this means immersion so that the chemical can penetrate the material being immersed.
Why not try a non penetrating chemical like Calcium Chloride crystals or Silica gel crystals or even Table salt where the use of these does not penetrate the internal structure and the moisture will still be absorbed.Thereby not introducing a liquid and soaking to directly affect the gems internal structure.Thats not going to help your oiling issues though.

Just because everyone else does it doesnt mean we all should.
Well thats another 2c which makes 4c on this topic but in Aust 5c is the lowest denominator.


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 Post subject: Re: Ethiopian Opal Agony and Ecstasy
PostPosted: Wed Sep 14, 2011 8:24 am 
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InTheDark wrote:
lightspeed wrote:
Cutting opal and ending a human life is not a comparison ,not even the same ballpark.I believe that topic is covered by various other forums and am sure it has no part in gemology or lapidary arts.


I'm certain if you read my post more carefully you'd discover I made no such comparison.


Perhaps the choice of example was not the best. Unfortunately it did seem to come across as a comparison and rather tasteless. But I'm sure no offence was meant nor was taken.


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 Post subject: Re: Ethiopian Opal Agony and Ecstasy
PostPosted: Fri Sep 16, 2011 1:25 am 
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I only did the milky to clear base material. It returned to all of its original color play IIRC. I have never had an issue with losing the color play with the Opticon treatment. You can have them end up more milky vs. totally clear if you get too much heat while soaking them though.

As for soaking in acetone and called it a treatment!!?? Sorry, but that is a bit overboard to say it politely. If you want to start considering these treatments then EVERY SINGLE stone out there is treated, period! Almost ever single stone out there is soaked in something to clean it after mining! Tourmaline often soaked in Muratic Acid, corundum in hydrochloric and/or SIOL or Oxyalic Acid, quartz is soaked in SIOL or Oxyalic Acid, and the list can go on forever. So, if soaking in a cleaning chemical is a treatment, then there really are NO such things as untreated stones. Not to mention, if you wish to get this technical... A faceted or cabbed gemstone is treated as well even if no other treatments existed. A treatment is defined as something that changes the appearance of the gemstone in order to gain beauty, which in turn causes it to gain value(in most cases, except extreme treatments like glass filling and such)... Faceting or cabbing or even simply tumble polishing exposes the gemstones to all kinds of chemicals, solvents, abrasives, and the act of cutting and/or polishing the stones is in fact significantly changing their appearance(far more then most standard treatments do) in order to increase beauty(in most cases..lol) and increase their value, the same exact point of normal treatments. So, by technical definitions, faceting, tumbling, and cabbing are all simply treatments as well. ;)

I am all for full disclosure on treatments! Everyone knows that, but there is a line that shouldn't be crossed. I mean, come on, ALL opals should be seasoned anyways, but due to the nature of hydrophane opals, soaking in acetone, draws out the moisture much more readily and can cause them to become seasoned in days versus years. Yet it changes nothing to their appearance, increases stability, does nothing that sitting them in a dry area/room(dehumidifier) for 6mths+ doesn't do in the same way essentially. CA is used to dop them, and they get soaked ion Acetone to remove the CA typically anyways. I don't understand the issue here.

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 Post subject: Re: Ethiopian Opal Agony and Ecstasy
PostPosted: Fri Sep 16, 2011 12:14 pm 
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As for soaking in acetone and NOT calling it a treatment,sorry thats a bit overboard to say it politely!!??
You are soaking to improve the appearance and properties of a gem.
You are drying it to restore its colour,also removing water from the stone, altering its properties artificially.

Franks dictionary of Gem terms,
TREATMENT:Is the process of artificially altering and improving the appearance and properties of gem materials.

Sorry swish i understand your point and understand what treatment entails.If you had an emerald or ruby and you soaked it in acetone ,it would be to probably remove a dye oil or epoxy from the interior of the gem.Same principal, you are removing from the internal of the opal.
If someone handed you an emerald sapphire or ruby and told you it was treated,do you throw your arms in the air because it has been cut and polished and cleaned or are you more likely to be thinking it has been enhanced,i think the latter.
I understand your stance on a technical point swish but if simply cutting using refined kero is treating an emerald you wont get me to see this one differently you and whoever else can simply do as you like, it bothers me not. 8)


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 Post subject: Re: Ethiopian Opal Agony and Ecstasy
PostPosted: Fri Sep 16, 2011 1:38 pm 
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Acetone is not a treatment. It is not even slightly permanent. All you need to do is drop the stone back in water for 20 minutes and you are back to where you started.

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 Post subject: Re: Ethiopian Opal Agony and Ecstasy
PostPosted: Fri Sep 16, 2011 8:37 pm 
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Oiling a ruby or emerald is not permanent either,all you need to do is drop the gem back into acetone for 20 minutes and the oil is gone.Soaking a gem in acetone under the definition of terms is a treatment no matter how small or technical you think it is.
There are several ways to dry out your gem,none of which are applying a solvent to the internal structure,directly messing with the internals of a gem structure is treatment.


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 Post subject: Re: Ethiopian Opal Agony and Ecstasy
PostPosted: Fri Sep 16, 2011 9:18 pm 
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I'm thinking this might need to go under the Treatments forum.

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 Post subject: Re: Ethiopian Opal Agony and Ecstasy
PostPosted: Sat Sep 17, 2011 1:49 am 
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Two old diggers overheard at the Digger's Rest Hotel:
"Hey Blue. Did'ya ere some blokes found some new road base they're callin opal?'
"Nah".
"Yeah, got from Afreekar. They reckon it's so dripping wet they gotta soak it
in nail polish remover!"
"Wha' for"?
"Dunno. They say to get the water out, but then they soak it in water again to put the water back in".
"Sounds a bit nuts to me. But I tell ya what, if they can soak the grey outta potch and put a bit of nail polish colour back in, then they'll be onto somethin".


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