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Can a Jewelers Torch or Soft Flame Negate Unheated Status?

goldstein

Rough_Rock
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Nov 19, 2014
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If a gemstone like a sapphire, is exposed to a jewelers torch or soft flame for less than 10 seconds for repair work on a prong.

And said sapphire is unheated and unenhanced. - Would it negate the unenhanced and unheated status of said stone even though the stone wasn't damaged, changed colors or cracked nor any changes in dissolving the inclusions?

Would it dissolve the crystalline structure or change the crystalline structure?

Would AGL, GIA or any reputable lab be able to pin point the heat on the stone and conclude possibility of heat treatment even if it's low heat?
 

goldstein

Rough_Rock
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Re: Can a Jewelers Torch or Soft Flame Negate Unheated Statu

Is a sapphire which unheated and exposed to heat from a torch or soft flame - dangerous?

Can it damage it? The clarity? Color? etc?

If an unheated sapphire ne is exposed to heat during repair and no damage or color change is noted; Is the sapphire good?
 

LoversKites

Brilliant_Rock
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Nov 16, 2013
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Re: Can a Jewelers Torch or Soft Flame Negate Unheated Statu

I don't think so but I'm no expert. From what I know low heat is still at 400+ degrees Celsius, and typical heating is done at 1800 or so degrees Celsius... And they remain in that temp for a longer time.
 

ElleK

Shiny_Rock
Trade
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Re: Can a Jewelers Torch or Soft Flame Negate Unheated Statu

When a stone is on a dop, the temperature it's exposed to is about 400 degrees, and that's just during cutting due to friction. LK is right that heating sapphires for improvement in appearance is at a much higher temperature.
 

LoversKites

Brilliant_Rock
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Re: Can a Jewelers Torch or Soft Flame Negate Unheated Statu

ElleW|1424419438|3835251 said:
When a stone is on a dop, the temperature it's exposed to is about 400 degrees, and that's just during cutting due to friction. LK is right that heating sapphires for improvement in appearance is at a much higher temperature.

Interesting, I had no idea. Around what temperature is considered low heat?
 

chrono

Super_Ideal_Rock
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Re: Can a Jewelers Torch or Soft Flame Negate Unheated Statu

Firstly, I am surprised a bench will attempt to fix a prong using a torch with the stone still mounted. What if it was a glass filled ruby? The stone will be ruined. A blue zircon could turn green. In terms of the sapphire, you are fine. That said, from all the threads you started recently, I would start looking for a different jeweller/bench.

LK,
Corundum low heat = 800 to 1200 degrees C
 

LoversKites

Brilliant_Rock
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Re: Can a Jewelers Torch or Soft Flame Negate Unheated Statu

Chrono|1424437337|3835296 said:
LK,
Corundum low heat = 800 to 1200 degrees C

Thanks.
 

2Neezers

Brilliant_Rock
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Re: Can a Jewelers Torch or Soft Flame Negate Unheated Statu

I just dropped a sapphire off to be mounted today in a setting that may need to be re-tipped. In talking to the bench jeweler he mentioned that he does not use high heat around sapphires because it can cause "what will almost looks like white spots in the stone", and instead he uses an alternative method. I didn't think to ask more questions about what he said because I was in a bit of a hurry, but he sounded confident in what he was telling me.
I know this doesn't answer your question regarding unheated treatment status, but his comment led me to believe it best for bench jewelers to keep high heat away from sapphires overall.
 

2Neezers

Brilliant_Rock
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Re: Can a Jewelers Torch or Soft Flame Negate Unheated Statu

Curiosity got the best of me and I had to look in to what the jeweler told me further :) .
Here is a link to an interesting article explaining how a bench should handle heat when working with corundum and some of the problems that can arise if they are not handling it properly. I find the exploding crystals info pretty interesting.
http://www.ganoksin.com/borisat/nenam/ajm-corundum.htm
 

goldstein

Rough_Rock
Joined
Nov 19, 2014
Messages
53
Re: Can a Jewelers Torch or Soft Flame Negate Unheated Statu

Thanks for the replies much appreciated.

I look at my sapphire carefully and no problems with his procedure. I don't see any white spots, cracks or inclusions which were not there nor any changes in previous inclusion. No changes in color or color zoning either. Nor any burns.

He used a soft flame but not a torch and only for a very few seconds around the stone; not directly.

And I believe he used it to dry the adhesive to hold the pendant on a wood. He didn't want to use a plier since the back part of the stone slightly protruded outwards from the back of the pendant to touch the skin.
 
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