Banten opal (solid opal)

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Shea_O
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Re: Banten opal (solid opal)

Post by Shea_O »

Iskandarman wrote:Just filling the crack for crystal opal...
For the matrix types, I coats them with cyno and repolished again until mirror-like finish


Thank you for this information, I had not yet heard anyone definitively confirm that cyano can polish to a glossy glass-like surface.


I would recommend looking into using a vacuum seal to force the cyano into the cracks

get some plastic vacuum bags that have the nozzle to attach a vacuum to, place some cyano into one of the bottom corners of the bag and drop the opal into the cyano (submerge/coat the stone) and then draw all the air out. The vacuum seal will pull the cyano into the cracks of the stone and then you can remove the stone and cure the cyano. I caught wind a while back that some of the mines in the Virgin Valley, Nevada use starbond/cyano in this way.
Iskandarman
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Re: Banten opal (solid opal)

Post by Iskandarman »

Thanks... That's sounds great! Vacuuming will improve the filling effect.
Iskandarman
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Re: Banten opal (solid opal)

Post by Iskandarman »

Contraluz Banten opal... I am feel happy with these very stable contraluz. Now I know that contraluz came from the core of fossil wood opal limb cast.
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Freeform contraluz Banten opal 9.5cts
Freeform contraluz Banten opal 9.5cts
Faceted Banten opal 6.6cts
Faceted Banten opal 6.6cts
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PinkDiamond
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Re: Banten opal (solid opal)

Post by PinkDiamond »

That stuff sets up so fast I'd be afraid I'd CA the opal to my hand or the like. :lol:

They're beautiful, and I love the faceted one. Did you facet it yourself? If so, nice going! :)
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SwordfishMining
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Re: Banten opal (solid opal)

Post by SwordfishMining »

The CA does not treat the opal itself. It does not work on opal that has been oil impregnated or glycerin or stored in mineral oil, what ever. That does soak into the gem opal and oozes out behind the treatment put on later. It polishes off the face of the opal unless the layer is so thick you are polishing the layer, then anti yellowing properties are more important than fracture sealing. Vacuum does do a better job and is a lot more intensive for hours involved. heating the resin in a jar with the opals then sealing it also pulls in the epoxy resin or CA.
There is not treatment needed on stable opals and once dried, cut and polished, why treat them if you don't know they will crack, by already having cracked? I only treat non naturals to save matrix opals or real bright crazy ones. Nothing, I mean NOTHING even hxtal hides a crack thru a gel gem perfectly.
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PinkDiamond
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Re: Banten opal (solid opal)

Post by PinkDiamond »

Especially with a non-surface reaching interior craze, with no entry from the surface, there's little that can be done without further damaging the stone.

Yehuda is the brand of fracture filling that was created for diamonds, which can often have an interior craze, so they laser drill down to the fracture, and begin filling with a process that's pretty much just like a windshield repair, where the filling has a similar refractive index to diamond, so the crack seems to disappear, just like on a windshield.

The filler is said to be a lead oxychloride glass, which has a fairly low melting point, and another diamond filling company is said to use lead-bismuth oxychloride glass, but the formulas are proprietary information, so it's anyone's guess, but it might work on opal if you can get one of the companies to do it for you. Even then, though, there's always the concern about yellowing, and the filler can be damaged, and need to be redone. For instance leaded-glass-filled rubies literally disintegrate in such common things as lemon juice, and household products, leaving the stones looking quite the mess.

Oh, and the filler is known for its 'flash effect', which can be detected by a trained eye with magnification, as it gives off bright flashes of color such as electric blue, or ultraviolet, but also can be orange or yellow, that can be seen as flashes of color when viewed nearly parallel to the plane of the filled fracture, and I would think that those flashes of color could be mistaken for colors within an opal.
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Iskandarman
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Re: Banten opal (solid opal)

Post by Iskandarman »

Oh... Any better advise on improving crazing appearance or to stop crazing moving forward deeper? :)
Iskandarman
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Re: Banten opal (solid opal)

Post by Iskandarman »

I wish to see some cabbed virgin valley opal in all variety from crystal to wood
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Re: Banten opal (solid opal)

Post by Iskandarman »

Here the example of Banten Precious fire opal. Stable and extremely glassy transparent material. Weighted 20.2 carats, very large for Indonesian opal.
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Color play under sunlight.
Color play under sunlight.
Banten Precious fire opal
Banten Precious fire opal
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SwordfishMining
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Re: Banten opal (solid opal)

Post by SwordfishMining »

Most of my pictures are RAW files and wont up load here. You just have to go to WWW>virginvalleyopal.com or search here in the threads or go to the Virgin valley opal mines pages on facebook or online. There are hundreds of pictures from digging to sold.
I'll jump over my shadow. https://www.virginvalleyopal.com"
Opals & more at my ESTY store https://swordfishmining.etsy.com"
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