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Author Topic: What would you do?  (Read 489 times)

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ileney

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What would you do?
« on: September 01, 2017, 10:33:03 AM »

I've read the Paul Downing book on cutting opal and practiced quite a bit, but I still often seem to get hung up on opals midway, something that never happens with other stones. With other stones, even really nice vintage Marlborough chrysoprase, I'll often ruthlessley cut away any imperfect areas, even when the color is really fine, if I think I can get a perfect small stone.  I can't seem to get myself to do that with opal when it has good play of color. So here is a faced opal. The front looks great IMO. I actually ground through two different color lines to create a larger faced stone (the color lines waved a bit), but it pretty much has color completely covering it with no dead spots. The problem is the back which has sand spots but also has great color due to a thin color line there which I have now faced but haven't finished (and I'd love a two-sided stone).
Sorry for the poor pictures. I am still using my iphone 5 and making no adjustments to the photos after, so they aren't the best.

Question- Should I:
a) leave it as is, polish it with the sandspots in place and cover them with a unique setting
b) try to carve out the sandspots and do some sort of carving on the back, possibly risking getting cracks because it will then be quite thin at that tip and then could require reshaping
c) grind the back down further, making the stone much thinner and probably losing much of the color on the back
d) something else
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gemfeller

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Re: What would you do?
« Reply #1 on: September 01, 2017, 11:12:19 AM »

I don't know how others feel about this but I've always likened opals to automobiles:  if the top part looks great, who cares what the undercarriage looks like?  Maybe it would matter if you entered your car in a concourse d'elegance but otherwise it's not a big deal IMO.

Of course much depends on the method of setting.  If the stone will be in an open-bottom setting or a prong setting that will reveal views of the stone's sides and bottom, it's a different matter.  I think I recall reading much the same opinion in one of Downing's books but it's been a while since I
went through them.  Of course I wouldn't value a stone with a sandshot bottom the same as a clean one, especially if the sand showed as dark spots through the top in transmitted light.

I teased the stone shown here out of a sandshot nobby from L.R.  I understand the sandy bottom will affect value, but I'm not prepared to toss the stone because of the sand.

Op 32a.jpg
*Op 32a.jpg (81.14 kB . 350x546 - viewed 158 times)
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rocks2dust

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Re: What would you do?
« Reply #2 on: September 01, 2017, 11:14:42 AM »

I'd leave it, and either place in a closed-back setting, or pierce the backing so that the pitted areas are covered.
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irockhound

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Re: What would you do?
« Reply #3 on: September 01, 2017, 12:10:46 PM »

I agree with leaving it and totally agree with the auto analogy.  Another option could be since it is the back just do a soft negative with burrs in the sand spots and polish them so there is no "imperfection" - you can still plan on setting with solid back setting.  Personal opinion is leave it and no one will care about the back as this isn't one of the top percentile stones where it would get such scrutiny but it is a nice stone. If it was a highest level stone I think we would have different opinions.
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Steve Ramsdell

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Re: What would you do?
« Reply #4 on: September 01, 2017, 03:32:09 PM »

I agree with others, leave it alone.  Many times I've had to take a completely polished stone and give it an emergency trim in order to mount it.  No one ever sees what is under the bezel or hidden by the base.  Enjoy.
Steve
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vitzitziltecpatl

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Re: What would you do?
« Reply #5 on: September 01, 2017, 04:29:32 PM »

What are the dimensions and thickness as it is now? You mentioned possibly doing a "double-sider", which would be nice if the inclusions don't go too deep. You can take a small LED penlight and sometimes see how deep they go if you hold the light tight against the surface. I've chased too many of them hoping they'd go away... .

The only one that worries me if you leave it as is - and it's a beauty - is the one closest to the edge. Looks like you have a good girdle, but an interruption in the bevel on the back edge. It doesn't look like a really weak pit, but anything near the edge makes me worry about future cracks. If it's been in it's present form for a few months it should be okay.

My inclination would be to leave it as is. The inclusions almost always go too deep to work them out.

hummingbirdstones

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Re: What would you do?
« Reply #6 on: September 01, 2017, 04:33:20 PM »

Add another leave it be to the list!   :icon_sunny:

The front of your opal is very nice.  Set in a closed back, bezel setting, no worries!
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Robin

gemfeller

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Re: What would you do?
« Reply #7 on: September 01, 2017, 04:34:58 PM »


The inclusions almost always go too deep to work them out.
:Worthy: Spoken like a battle-scarred veteran opal cutter!
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ileney

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Re: What would you do?
« Reply #8 on: September 01, 2017, 09:22:25 PM »

Many thanks for all the advice folks! I think I will leave it be, as advised. Gemfeller, I love love love your LR Opal. From the back, you would never expect it to have come out so well!
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gemfeller

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Re: What would you do?
« Reply #9 on: September 01, 2017, 10:13:36 PM »

Many thanks for all the advice folks! I think I will leave it be, as advised. Gemfeller, I love love love your LR Opal. From the back, you would never expect it to have come out so well!
Thanks.  That was one of the most delicate and edgy cutting jobs I've ever done.  I spent a long time sneaking up on the color and hoping against hope I could avoid sand showing on top.  I actually had a hard time believing the result. 

Cutting nobbies that make it past the sharp eyes of the L.R. miners to the U.S. can be harrowing and a tease.  Often they contain a maze of sand with only traces of uncuttable precious opal that hint at what might be possible.   
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Bluetangclan

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Re: What would you do?
« Reply #10 on: September 03, 2017, 08:21:26 AM »

Leave the bottom alone. No one looks at the back, especially in a closed setting. Words from my instructor. Unless its especially jagged to the point it wont fitting in a setting, it wont negatively affect value.
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John Robinson

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Re: What would you do?
« Reply #11 on: September 04, 2017, 11:05:17 AM »

I should not be saying anything being a novice - I would make a two- sided product. The buyer could be sold on the idea of getting two opals for the price of one. Also IMO the second side with the bigger highlights is worth looking at and would be more noticible from a distance. I have several nice pin opals, that one can only see the color play from closer than 6 inches.

To me the farther away one can tell a stone is an opal the better it is. I have a collection now of tiny little high quality opals that I have to use a loupe to explore - but I do not know how many other people would consider an opal to be of worth if one could not see the details with the naked eye (?)
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ASO

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Re: What would you do?
« Reply #12 on: September 12, 2017, 12:52:46 AM »

Over the long run the amount of cts you can loose from chasing double sided stones will be allot more than any extra money you will make from actually finish the backs all the way.  The most important thing for the back is making sure that the stone will sit well in a piece of jewelry.  98% of your value is on the top and setting edge of the stone.  When you cut stones from Mintabie and Andamooka you can actually leave the hard natural sandstone on the back.  Take a look at The Royal One its a big black opal nobby worth 3.5 million and has sand on the back.
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ileney

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Re: What would you do?
« Reply #13 on: September 13, 2017, 05:33:56 AM »

Thanks. Just looked. Isn't that the same stone they were marketing as "my precious" a year or so ago and claiming it took two years with a flexshaft and dental burrs to carve? Orare there two so similar? People can claim a stone is worth $3 million, but I believe it when the market proves it.
http://www.luxury-insider.com/luxury-news/2013/06/my-precious-us3-million-rare-black-opal
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ASO

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Re: What would you do?
« Reply #14 on: September 13, 2017, 10:10:47 AM »

You got it that's the same stone I think the miner was only payed $300,000 for it they have put allot of marketing into it.  3mil does seem like a lot for a stone with no red in it at all but taking it on a world tour to all the famous billionaire hangout spots is a good way to try and find how high the sealing is.  I think the point of all this was that very valuable stones can still have some sand on the back.
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