Speaking of rainbows - I got my results - kind of

[colorluvr]

For those of you who missed the original thread - here is the link:

https://www.pricescope.com/community/threads/speakings-of-rainbows.142323/

I took the stone to Portland yesterday and the gemologist told me that she was 90% sure that it was completely natural. She would not commit to 100% positive without extensive, expensive testing, but she said the reason she felt 90% sure was that she found a "fine fingerprint inclusion" in the stone that was consistent with the type found in natural quartz. She said that fingerprint inclusions are sometimes found in the synthetics, but that they are more "globby" (her word) and not fine like the one in mine, which made her feel comfortable to state that it was natural. She also did not see any of the telltale signs of a synthetic.
She said if the stone was perfect (had no inclusions), she would not have been able to be as certain, but because she was able to see the inclusion under very high magnification, and that it was consistant with what was found in natural quartz as opposed to the type found in synthetic quartz, she felt it was natural. She did state however, that the synthetics are getting better and better and harder to detect.

So.... I''m happy with the results, and considering what I paid for the stone, I''m comfortable keeping it with a 90% certainty rating. If it were an expensive or rare stone, then I would go the extra mile and expense to get that 100% certainty, but with a fun stone like this one, I''m content.

In fact, after I got home, I bought ordered another one, only this one is smaller (aprox. 10mm) and it is a squarish EC cut that I hope to put in a ring some day. They are not on top of my list of projects, but I didn''t want to miss this last one because it was the size and color I wanted (more purple) so I nabbed it.

Squarish EC cut ametrine (I should get it by Monday)

 

[colorluvr]

BTW, the seller told me that the off look (not square) in the middle of the picture is reflection and that the stone is well cut.

 

[Bella_mezzo]

Very cool!!!! I don''t care what they are or if they are synthetic or not...they sure are pretty!

Was she able to say what kind of treatment, if any, she thought they had received?

 

[colorluvr]

She could not detect any treatment. Her comment was that she could say with 90% certainty that it was a 100% natural stone.

 

[Upgradable]

This is going to be such a distinctive piece! I hope you''re going to go very clean and plain with the mounting. Don''t distract from that amazing bi-color!!

 

[gsellis]

That is a very nice one. They cannot all be 50/50. And whoever did it went for clean. So it is cool when the colors shift.

 

[colorluvr]

Date: 5/13/2010 9:28:53 PM
Author: Uppy
This is going to be such a distinctive piece! I hope you''re going to go very clean and plain with the mounting. Don''t distract from that amazing bi-color!!

Yes, I plan on simple setting for both of the stones... they are big enough and colorful enough, they don''t need extras...

 

[Stone Hunter]

That''s going to be a stunning set of stones. Pendant and ring?

 

[marcy]

That is so very cool!

 

[Barrett]

I am still a little skeptical..a 10ct ametrine would take a 47ct piece of rough to cut..a clean piece of ametrine rough is few and far between..I have looked at thosands and thousands of amethyst rough anbd rarely do you ever see even a flawless amethyst crystal in the 45+ct range..I looked at a 20 pound burlap sack full of top grade ametrine rough, bought directly from the owner of the Anahi mine, that was picked up from him 15 years ago in Tucson at the ammy kings house(old JXR mine owner)I hand selected 4 of the absolute best pieces and none looked close to what you got..it was all old mine rough..all facetgrade and was half the stock the owner brought to Tuscon 15 years ago(of course he had sold somne pieces so maybe there were a few real good ones but 20 pounds is a lot of rough) Here is what Tony the GemDr. even said in a discussion about ametrine i found..and you know Tony has seen lots and lots of rough
[about ametrine]"I have never seen natural rough that had anything like straight and sharp let alone flawless and evenly coloured. Considering the relatively tiny quantities of this stuff that has ever been found...." Not saying yours isn't but just a lot of things that would give me pause..how much did you pay for it..that might be a clue? I have bought and sold a few ametrine roughs in my day and the price you paid for the finished stone would be a good indicator but not definitive of course

 

[gsellis]

Date: 5/15/2010 12:27:10 AM
Author: amethystguy
I am still a little skeptical..a 10ct ametrine would take a 47ct piece of rough to cut..a clean piece of ametrine rough is few and far between..I have looked at thosands and thousands of amethyst rough anbd rarely do you ever see even a flawless amethyst crystal in the 45+ct range..I looked at a 20 pound burlap sack full of top grade ametrine rough, bought directly from the owner of the Anahi mine, that was picked up from him 15 years ago in Tucson at the ammy kings house(old JXR mine owner)I hand selected 4 of the absolute best pieces and none looked close to what you got..it was all old mine rough..all facetgrade and was half the stock the owner brought to Tuscon 15 years ago(of course he had sold somne pieces so maybe there were a few real good ones but 20 pounds is a lot of rough) Here is what Tony the GemDr. even said in a discussion about ametrine i found..and you know Tony has seen lots and lots of rough
[about ametrine]''I have never seen natural rough that had anything like straight and sharp let alone flawless and evenly coloured. Considering the relatively tiny quantities of this stuff that has ever been found....'' Not saying yours isn''t but just a lot of things that would give me pause..how much did you pay for it..that might be a clue? I have bought and sold a few ametrine roughs in my day and the price you paid for the finished stone would be a good indicator but not definitive of course

I''m not that skeptical. Go look at the ametrine page on Jeff Graham''s site. Jeff''s was really top grade and he was charging up to $5/ct for the rough. He had a couple of 100+ct pieces that I lusted.

 

[Barrett]

I am when 98% of the ametrine on the market is not "from the ground material"..thats a big number..it may just be the ghighest ratio of natural to man made of any gemstone(amount actually pulled from anahi /amount produced in china and russia) If you read the Rock & Gem I think it was 4 months ago(march '10) Jim Perkins even stated that almost all ametrine seen today is man made and you should assume yours is to " in 1990 the first synthetic ametrine appeard on the market..there is also ametrine that is produced by heat treating and irridating color zoned amethyst...

"unless you dug the rough yourself you should probably assume it's treated or synthetic"[end quote]..that was from jim pekins in December 2009 R&G and in the next months issue(january 2010) had a rebuttal by none other than Rodney who has the 20 pound Burlap sack i looked though saying that "he did not like that statement as he held a large amount of natural ametrine himself and thought that would turn people off to the fact that some folks do have natural ametrine..so as you can see..Jim even says "unless you dug it yourself than probably best to assume it's syn. or man made..it's one of those stones that will give pause..so even the late jeff graham..unless he got it in tuscon from the anahi mine owner, tripped down the bolivia, or had is tested via EDXRF or IBA then know way of knowing..even so the latest reports from 3 years ago stated the mine had almost run it's course and almost no "good" material was found or is founbd..that was 3 years ago but i can't confirm that

 

[RockHugger]

Date: 5/15/2010 12:27:10 AM
Author: amethystguy
I am still a little skeptical..a 10ct ametrine would take a 47ct piece of rough to cut..a clean piece of ametrine rough is few and far between..I have looked at thosands and thousands of amethyst rough anbd rarely do you ever see even a flawless amethyst crystal in the 45+ct range..I looked at a 20 pound burlap sack full of top grade ametrine rough, bought directly from the owner of the Anahi mine, that was picked up from him 15 years ago in Tucson at the ammy kings house(old JXR mine owner)I hand selected 4 of the absolute best pieces and none looked close to what you got..it was all old mine rough..all facetgrade and was half the stock the owner brought to Tuscon 15 years ago(of course he had sold somne pieces so maybe there were a few real good ones but 20 pounds is a lot of rough) Here is what Tony the GemDr. even said in a discussion about ametrine i found..and you know Tony has seen lots and lots of rough
[about ametrine]''I have never seen natural rough that had anything like straight and sharp let alone flawless and evenly coloured. Considering the relatively tiny quantities of this stuff that has ever been found....'' Not saying yours isn''t but just a lot of things that would give me pause..how much did you pay for it..that might be a clue? I have bought and sold a few ametrine roughs in my day and the price you paid for the finished stone would be a good indicator but not definitive of course

There are ALOT of synthetic ametrine out there right now. I personally wont buy ametrine because of this reason. Too hard to tell, and too expensive to know for sure. But you can get lucky and find a natural one. I have a 75ct one that I am getting set (I actually just posted about it then saw this!) that came back as natural. So you never really know!!

Yours is beautiful, nice color! Love it no matter where it came from!

 

[colorluvr]

First off, I need to correct an error on my previous posts, my supplier buys these stones directly from an American cutter who lives in Brazil, not Bolivia. The stones are coming directly from the Anahi mine from a mine rep who brings them to the market in Brazil.

I didn't mean to start a debate here, but here are some links that my supplier gave to me for backup to share. I know those of you who are "in the know" are already familiar with this info, but those of us who are just "somewhat informed" consumers like me, might see something they didn't already know.

Info about the mine: http://www.ametrine.com/ametrine/index.html

Info about some of their rough and some finished stones: http://www.gemfacetingrough.com/ametrine/

2004 article from Professional Jeweler: http://www.professionaljeweler.com/archives/articles/2004/jun04/0604gn.html

some rough for sale: http://www.mineralminers.com/html/amtlrgh.stm

"I am still a little skeptical..a 10ct ametrine would take a 47ct piece of rough to cut"

According to the cutter, it takes a 30ct rough from good quality stock to get a 10 ct cut gemstone.

"I looked at a 20 pound burlap sack full of top grade ametrine rough, bought directly from the owner of the Anahi mine, that was picked up from him 15 years ago in Tucson."

It is my understanding from the articles I have read and my supplier, that this current high quality rough has only been coming out of this mine in the last few years.

"I am when 98% of the ametrine on the market is not "from the ground material"

If he had gotten these stones from a broker, then I would agree that there is a huge chance that the rough would not be natural, but he goes direct (he was introduced to this cutter by a highly respected gem seller who has been highly recommended on this forum) and he is actually getting one custom cut right now (by this cutter) for a client that contacted him after they saw pictures of my stones. There aren't any other middle men, so he is able to keep his costs reasonable.

As far as the quality of my first stone, I got the best of the best because I knew he was getting them before they hit his website, and I got to choose the best of the best of his first shipment. I believe he is getting another shipment soon.

So, for a beautifully cut stone, at a reasonable price, that a professional gemlab stated with 90% assurance that the gemstone was 100% natural, and buying from a seller that I trust and who buys directly from a cutter in Brazil who receives his rough directly from the mine, I'm content that I got a beautiful natural stone at a reasonable price.....

I'm new to this forum, and certainly don't mean to stir up controversy or question any of the longtime respected members. I guess we'll just have to agree to disagree on this one.

 

[colorluvr]

Sorry about all of the spaces between lines in that last post..... didn''t mean to do that

 

[Barrett]

So your cutter is getting a 30% return on his stones which many of the precision cutters on here wish they could get except on the occasional tourmaline or emerald..i must say that is impressive..i never ever got a 30% return on a cut stone..I know John LeBourgeois can pull a 32-33% off a tourmaline or emerald due to the long shape using a bar cut or similar cut..so if he is getting 30% on a regular basis then i will have to know his secrets..I think a constant 25% return is real good on any stones and thats if it's pretty much preformed which with ametrine it usually is as most pieces are presawed so thats entirely possible especially with ametrine

"It is my understanding from the articles I have read and my supplier, that this current high quality rough has only been coming out of this mine in the last few years." Can you please cite these articles or reference them for me please?

"but he goes direct (he was introduced to this cutter by a highly respected gem seller who has been highly recommended on this forum) and he is actually getting one custom cut right now (by this cutter) for a client that contacted him after they saw pictures of my stones. There aren't any other middle men, so he is able to keep his costs reasonable."

This is not direct..how this could ever be considered direct..this is the most common misconception..I get my "stones" direct from pakistan..who my guy gets from the miner who brought it from the mine..and he still gets fakes handed off..there is no true assurance..you may trust your contact and he may be as honest as it comes but he gets his stones from somewhere and that person gets his stones from somewhere..this doesn't mean anything..thats how it works with fakes and synthetics..never ever believe the whole.."well my dealer this" or "my dealer that" once again you are assuming something that shouldn't be assumed..if it was a spinel or tourmaline then yea..would be fine but you are talking about an 10ct ametrine..flawless..color split right down the middle..not saying it isn't but I would lean towards the syn before i would the real deal. Getting it direct would be ordering it from the Rivero family themselves..there is not a rep. from the mine that brings them to brazil..the dealers that do get it order it and get it shipped..

"So, for a beautifully cut stone, at a reasonable price, that a professional gemlab stated with 90% assurance "
What gemlab? it was a person with a microscope..if it was that easy then IDing syn vs. natural ametrine wouldn't require actual real testing by chemical analysis machines..then anyone with a microscope could tell. You see hugger got hers checked out properly..it was very doubtful it was real at first but instead of her "assuming" it was natural she got it tested and it was real. There really is no 90% assurance..it either is or it isn't. Once again..not saying yours isn't..I hope it is very much so..i think it's a fantastic looking stone but just want to point some things out that would cause me to give pause..Here is a direct quote from Jeff graham from Tucson 2009 "Ametrine - Supply is zero, none, nada, zip... There was certainly no rough around" That was last year..at the largest gem show in the world that the Rivero familky always goes to.
I have spoken with Mr. Riveros son through email 2 or 3 times..they are the only folks I would trust getting real ametrine from..and my buddy Rodney, Rick Stinson, and Dan Starr. Once again not saying yours isn't as you can't ever be sure without a full lab report with ametrine but just wanted to get some facts out there

 

[LD]

Colorluvr I''d just like to add ................... treatments actually can''t be detected by looking (even under high magnification). The person you took your stone to was wrong if he/she intimated that he/she was almost sure it was natural. This is a very dangerous assumption to make on the basis of seeing a fingerprint. You can get inclusions in Rubies that have been dyed and filled - would that make a difference to the price? Yes, an absolute huge difference.

I''m glad however that he/she told you that he/she couldn''t be certain and this was the right thing to do. If this was a cheap (by your standards) gemstone and you''d be happy for it to be a synthetic if it turns out that way then just enjoy your gem. However if you paid what you would consider to be a large amount for your gem then I would urge you to get it checked professionally at a laboratory. Only a laboratory can give you a definitive "yes, it''s natural".

I also have to say that other information from your appraiser is "off" and I would urge you to listen to those who have posted above who are lapidarists and used to buying, working with and cutting rough.

 

[Barrett]

yes..yes please don''t think i am picking on you..I really really hope it''s natural..I just want not only you but all the others who happen on this post or are thinking of buying an ametrine to know the risk and rewards associated with them..your contact/cutter/dealer is a much better person to buy from than say ebay or at some jewelry store ..so you went the rght route with that..

 

[LD]

Just so you know where I'm coming from also, I have two Ametrines - one almost the same size as yours. I paid $90 for the two of them so have never bothered to have them tested as it would cost more to do so than I paid for them! They both have inclusions but who knows! I don't care either way because they are very pretty. They were bought as natural but are most probably synthetic.

The emerald cut is 84ct and the kite shape is 28.28ct.

Edit: Oh my goodness how did that photo come out so large - apologies!

 

[Arkteia]

Amguy, one strange question. If an ametrine comes from earth, won''t the line separating the amethyst and the citrine be curvy and vague, not straight? In most of ametrines I saw, there was such a distinct separation between the two. In a real one, I''d expect the colors to blend into each other.

 

[Barrett]

A majority of the natural ametrine is called "blended" which is a natural blending of the two colors or blending along the split..most of it is that..but when you buy from anahi..most of the time it's sawn and preformed so you either get blended or you can order bi-color which is already cut so the split is down the middle but it's almost never ever a stright perfect line,..has blending along the line..however small it maybe which is also the case with the russian material..thats why it's so hard to tell syn vs. natural..it's just quartz grown roughly the same way as in the ground..have a seed crystal but I am sure they have perfected the syn. by now..used to be able to see a small colorless zone around where the seed crystal(which was colorless) would have been placed....you must order direct from the owners ..a rough price on a 40-50ct bi-color piece of rough VVS would be around$90 -$105..thats direct price straight from the mine..tack on middle man prices if not direct..once again..if I got a flawless stone for on the cheap with a split down the middle then i would e suspect but you can get it..direct from the owners..oh..it's around..but for the amount thats floating around and the amount that comes from this one mine it shows that syn. run rampant...flawless rough with 50/50 color split but depending on what you paid for it woulod determine a lot of things from another source

 

[colorluvr]

Sorry I have taken so long to answer your questions... I was MIA over the weekend, and when I checked back in at the beginning of the week, the site was down... I''ll try to answer your questions... it may take a couple of posts to get it done, but I''ll do my best:

"It is my understanding from the articles I have read and my supplier, that this current high quality rough has only been coming out of this mine in the last few years." Can you please cite these articles or reference them for me please?

Robert Weldon''s article from 2004 with photos of some of the newer fancy cuts that are being made.
http://www.professionaljewel.com/archives/articles/2004/jun04/0604gn.html

This Caltech article stating "In a new area of the mine recently opened (1999) called Pozo Rico, a 4 x 3 x 1 meter cavern of crystals was discovered. Here are two pictures of the large pocket provided by the company..."

http://minerals.caltech.edu/ametrine/index.html

From the 2005 issue of colored stone:

"In the year 2005, the mine is expected to produce a total of 11 million cut stones in a variety of grades and sizes. This includes six million carats of amethyst, three million carats of ametrine, and two million carats of citrine. Approximately 60 tons of cabbing rough in mixed colors is also produced annually. The output at the mine has gone down in the last few years, and dealers are reporting a shortage of better amethyst rough, as well as ametrine. The company that operates the Anahí mine has created policies aimed at increasing profits which limit production in an effort to extend the life of the mine. This includes cutting more material locally and selling better rough material direct to select high-end designers and cutters, thus decreasing the amount of material available to the market."

http://www.colored-stone.com/stories/nov05/mining.cfm

Spring 2009 - Gem News International - Gems and Geology - pg. 63 & 64 (this is not available to everyone online, so I pull repost part of the article)

In August 2008, GIA staff members visited Anahí to videotape and report on the mine-to-market operations.... Production at the Anahí mine is lower than it was a decade ago, but Mr. Rivero maintains that is because greater efficiencies in mining, sorting, and cutting have reduced the
amount of rough needed for the value-added operations.....Nevertheless, the mine still produces some 2,500–3,500 kg of gem-quality material, from a total 120 tonnes of quartz mined each year. Amethyst averages the highest production (44%), followed by ametrine (33%), and citrine (23%); ametrine remains the most lucrative product. The proportion of ametrine has actually increased (from 20% a decade ago) because of Mr. Rivero’s success in marketing gems that do not necessarily show the traditional split in amethyst and citrine colors. In the early years of the
Anahí mine, ametrines were often faceted as emerald cuts showing a distinct color demarcation to mimic the appeal of bicolored tourmalines. But cutting ametrine for an even color split wastes much of the quartz. While “fantasy” cut gems have long ignored this purple-yellow color demarcation in favor of free-form shapes, Minerales y Metales del Oriente today focuses on a blend of colors in more traditional shapes (i.e., round, oval, or pear). This strategy maximizes yield. In addition to purple, the resulting mix of colors may exhibit “peach” or deep orangy red hues when viewed face-up (e.g., figure 11)."

I''ll post the pictures from the Gems and Gemology article in the next few thread.... to be continued.....

 

[colorluvr]

From 2009 Gems and Gemology article:

Figure 10. This tunnel at the Anahí mine exhibits the richness of the quartz deposit. Photo by R. Weldon.

 

[colorluvr]

Gems and Gemology 2009 article: Figure 11. Anahí mine ametrine is cut to maximize yield while also blending the yellow and purple colors. The 33.55 ct gem on the left was cut by Dalan Hargrave; the 44.23 ct concave-cut stone on the right was faceted in Bolivia. Both gems courtesy of
Minerales y Metales del Oriente; photos by R. Weldon.

 

[colorluvr]

"would be fine but you are talking about an 10ct ametrine..flawless..color split right down the middle"

The gemstone is not flawless, the registered gemologist (GIA) that looked at the stone found a small inclusion and the color split is not perfect along the middle.... here is a photo of the bottom of the stone showing that it isn''t truly a straight line split, even though it appears that way from the top....

 

[colorluvr]

I got the stone "looked at" at this lab. http://www.pacificgemlab.net/ All of the employees are GGs (GIA) and the person who sourced/cut the stone is also a GG (GIA).... The seller (the person I bought my two from) said he is getting a full certification report on one of the ametrines from the same lot.

So, does ANY of this prove that my stone is real - absolutely not, but it does add to my comfort zone. If I had paid hundreds of dollars for the stone or intended to resell it, I would definitely get the full certification, but I didn''t, so I''m ok with being "pretty dang sure" that the stones are natural.

 

[PrecisionGem]

As far as yield goes, I average around 33% over all the stones I cut. Some are as low as 15% some as high as 45%. I just finished up a Malaya garnet that I got 41% and it''s a round shape.

The key to high recovery is to only buy well formed shapes. A small time cutter who is selecting each piece rather than buying large lots can do this. I''ll pay more for well shaped rough, but to me it''s worth it in the long run.

 

[Barrett]

wow..nice follow up..well done..I have never seen that G&G picture before..so you didn''t get a cert. at PGL? How much did you pay for your stone?

 

[colorluvr]

Date: 5/21/2010 12:04:34 PM
Author: amethystguy
wow..nice follow up..well done..I have never seen that G&G picture before..so you didn''t get a cert. at PGL? How much did you pay for your stone?

No, their verbals are pretty inexpensive, but to get anything in writing it is over $100 and the stone cost me less than $200, so to me (for just personal wear) it wasn''t worth the money.

 

[Barrett]

great pics..thats a concave cut you posted, right? was wondering where you went to..the post sort of trailed off to the next page..figured you didn''t give up but must be MIA like you said. are those big ammy plates in that picture..heck one of those would be nice to have..look like Reel mine ammy''s