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Author Topic: Stone Cutting  (Read 445 times)

FlashGP

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Stone Cutting
« on: February 10, 2021, 10:50:26 PM »
Does anyone know of a Robert Cook at or near Glen Innes who cuts gems commercially?

 My wife was almost in tears tonight.  She picked her new ring up from the jewellers after having a red Zircon I cut set.  When she got home she found the cutlet had been rounded off.  It still pokes through the bottom of the setting into her finger so I am not sure if the polisher wore it away or it was ground off instead of the setting being made taller.

Anyway the jeweller said he could have it repaired by Robert Cook, who cuts Sapphires.  Apparently he can  “repair” the stone without losing any weight. 

Given I redesigned the pavilion to lighten the stone by getting rid of the pavilion fat and lowering pavilion and crown angles, I am dubious about this claim.

So before I let the jeweller have a go at having the stone repaired, I would like to know if the cutter is going to do a proper job, eg measure the angles and cut for optimal brilliance or simply try to hide the window by putting a row of cutlet facets at below CA I where the cutlet used to be.  Otherwise I’ll ask for my money back and compensation for the damage to the stone then recut it myself.
« Last Edit: February 10, 2021, 11:01:04 PM by FlashGP »
Yours Sincerely
Flash (Gordon)

Dihusky

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Re: Stone Cutting
« Reply #1 on: February 11, 2021, 04:17:20 PM »
Rounded culet, only way is to re-cut the pavilion on a shallower angle or try an add a new tier of facets which could look terrible depending on the pavilion design. It also has to lose some weight so the Jeweller's statement is total BS!

If someone cuts, there is no guarantee they can repair, totally different skill set.

Faceting Frank

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Re: Stone Cutting
« Reply #2 on: February 11, 2021, 08:04:11 PM »
You could cut a new row of facets below the C A frosted. Say 1200 grit to show a rose or star when looking from above.

FlashGP

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Re: Stone Cutting
« Reply #3 on: February 12, 2021, 12:47:46 AM »
Hi Frank,


I'll do a bit of modelling on my cutting instructions and see how it might look. 


The frosted dome is visible as a blob of fuzziness in the stone.  This afternoon the Jeweller suggested he could polish the rounded end.  This would only make the window more noticeable.
Yours Sincerely
Flash (Gordon)

Aussie Sapphire

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Re: Stone Cutting
« Reply #4 on: February 12, 2021, 10:58:03 AM »
Does anyone know of a Robert Cook at or near Glen Innes who cuts gems commercially?
 

sending PM
Aussie Sapphire - The Lapidary Warehouse

MakkyBrown

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Re: Stone Cutting
« Reply #5 on: February 12, 2021, 12:50:44 PM »
You could cut a new row of facets below the C A frosted. Say 1200 grit to show a rose or star when looking from above.
That could be the best option.
If you show me the design I can have a look at options. Might be able to use a small culet and push the pavilion angles in a bit without a huge amount of windowing. Just depends on how much they have ground off and how shallow your pav was to start with.
That is a very poor effort from the jeweler, as if they can repair without weight loss.
MB

RoughCreations

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Re: Stone Cutting
« Reply #6 on: February 12, 2021, 01:13:54 PM »
That is a very poor effort from the jeweler, as if they can repair without weight loss.
MB
Hopefully the solution wasn't going to involve sticking a bit extra on...
Rough Creations - Beauty from rough beginnings

FlashGP

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Re: Stone Cutting
« Reply #7 on: February 13, 2021, 07:42:24 AM »
Hi Makky,


I still have the diagram and did some modelling.  I can only reduce the angles 5% before it starts loosing its peformance, windowing is more than 30% at all tilt angles after a 10% reduction in angles.


There is some slight damage to the crown, looks like a slip while setting.  I noticed it when I inspected the stone with a loupe.


Yours Sincerely
Flash (Gordon)

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