Heated? UNheated? Gemstones? AVOID?

[MINE!!]

Is heated bad? Only for certain stones? What happens is heat is used? What are the consequences? Are some stones ok to be heated for treatment? Should I avoid all heated stones? HELPP!!!!!

 

[Layne]

from my humble undestanding...heating is not bad for the stone, it is used to improve the look. it is a matter of preference- if you care that the stone looks better because it was treated. when looking at colored stones it is best to assume the stone is treated unless told otherwise.

anything in particular you are looking at?

 

[strmrdr]

Buy the stone not the paper the paper just determines the price.
Iv seen total crud sapphires with higher price tags than awesome looking sapphires just because the cruddy looking ones were unheated and the great looking ones were heated.


Made no sense to me why anyone would buy the more expensive worse looking ones.
But then again i like synthetics.
And actualy in some cases prefere them.

 

[triphane]

I think it''s a matter of preference. but you should always have the right amount of information to satisfy your perception of value. Obviously a synthetic will be cheaper and very glitzy but a natural stone will have a deeper meaning and greater rarity. Sapphire or corundum is heated to improve color and clarity. The heating process is very harsh and should be considered in my opinion as recrystallization because the stones are heated to the melting point, but who am I? Other stones are not treated as harshly such as Tanzanite it has a minor heat treatment process. It is always best to get as much information before your purchase and remember a jeweler will love to sell you the synthetic because he makes more money from that sale even though it is less in price. Mining is a costly effort and that is why natural stones are more expensive.

 

[triphane]

Hey you could always go with garnet it is not treatable to my knowledge. Just a simple little silicate.

 

[lonewoodminer]

Hi all

Interesting subject - my opinion for all its worth is in line with triphane''s views. Buy natural if you can and only if you''re sure it really is. Basic heat treatment is normally okay and in sapphire and many other gems has been the norm for in some case hundreds of years, although we offer fully natural when possible. The main concern I have is when the original structure is altered (eg Beryllium treatment or irradiation). The best way of knowing this is to deal as close to the miner as possible. A reseller of gemstones/jewellery may have the best of intentions, but the number of hands a rough stone passes through on its journey to its final home as a finished gemstone or piece of jewellery would probably surprise most. These major alterations to the natural stone are probably okay but I fear many buyers are not aware of what they are actually buying.

I recently questioned a senior person in a large chain jewellery store in a nearby city whether the stone they were selling was natural or enhanched by any treatments - his answer was plain and blunt: "that a chain store like he worked for would only sell the best and what is heat treatment anyway?" He didnt know what he was selling and as far as he knew he was being fully truthfull! Doesnt help the buyer when the seller does not know the full story. We have had many similar experiences. Keep in mind that our perspective is from Australia where there is no legislation on full disclosure of treatments - the increased awareness of gemstone treatments in the US is probably largely due to this kind of legislation and I think we need a similar system in Australia for the protection of buyers.

We have little demand for totally natural sapphire in Australia as many buyers just dont know about the issue - all of our enquiry for this kind of product has come from the USA where consumers seem to be more informed about this issue. Most of our domestic customers are buying purely on price and looks - this is fine but it is better for everyone if they know the full story. Gemstone treatments are not totally bad as long as everyone has full information on which to base their buying decision.

Cheers Andrew Lane
www.aussiesapphire.com.au

 

[MINE!!]

WOW.. thanks Lonewoodminer!!!

 

[widget]

Date: 4/19/2005 9

2:46 PM
Author: triphane
Hey you could always go with garnet it is not treatable to my knowledge. Just a simple little silicate.

I''m not too sure of this, but aren''t demantoids sometimes treated/heated?

widget

 

[MINE!!]

Here are 2 ABSOLUTELY Gorgeous Stones from Richard Homer that I am looking into. They are both heated... But Richard said they are not heated Harshly... Tell me what you think...
Pic#1

 

[MINE!!]

Let''s try again Pic#1

 

[MINE!!]

#2

 

[MJO]

I like #2. Looks brighter to me.

 

[MINE!!]

Yeh.. it does look brighter... I think it is the Blusih undertones in the first that I like... But I love the brightness of the 2nd.. darn... Why can''t I be rich??????

 

[Sagebrush]

Widget,

As usual you have your ear to the ground. Latest industry scuttlebutt is that, yes, it is possible to heat treat demantoid garnet. Heard this in Tucson and got a confirmation from a big player in demantoid during the trip to Bangkok.

Don''t know much about it, seems like GIA and all the labs are playing catch-up on this. If its low temperature as with tourmaline and tanzanite it may not be detectable at all.

 

[MJO]

Richard,

You are correct. I''ve heard this for 2 years now.

 

[Richard M.]

All,

Heat treatment of some, but not all, demantoid garnet has very likely been done for as long as 100 years in Russia, dating back to Czarist times when the gem first achieved great popularity. It is indeed a permanent low-temperature process used to drive off the secondary brown colors. Demantoid from several other locations including Canada is also sometimes heated.

In 2003 the GIA reported on the rediscovery of an original demantoid source at the historic Kladovka Mine in Russia''s Ural Mountains. Apparently demantoid from this source does not require heating, the GIA said, unlike gems from the Karkodino Mine, also in the Urals and source of much of the Russian demantoid on today''s market. I''ve been looking since then for any tests that indicate heating but haven''t found any. Demantoid has been found in Russia, Canada, Italy, Iran, Africa, the U.S. and Mexico. Not all produce enough for commercial use however.

Richard M.

 

[fatafelice]

I''m new to colored stones, so I apologize if this has been covered before...

If sellers do not always know about or disclose the treatment of a stone, will you ever know? By that I mean, if you take a stone to be appraised, can the appraiser tell whether or not it has been treated in any way?