How do you feel about Be-treated/"Songea" sapphires?

[RedSpinel]

I first noticed this phenomenon about 7 years ago I guess, as I was browsing the internet for stones. I'd keep seeing this sudden, high volume of "Padparadscha" sapphires, and I was both puzzled and skeptical. It was hard to belive that there were all these seemingly cheap Padparadschas all over the internet! Plus, they didnt exactly fit the typical color I'd become accustomed to seeing in Pad, sapphires.

Soon after I read about what was happening here. Its been years now, but basically I read that some gem owner was trying to heat treat some sapphires, when he accidentally left some Beryl of one variety or another mixed in with the sapphires. Then while heating them, the proper heat for sapphires rose above the vapor temp of beryl, so the beryl vaporized, and chemically bonded with the sapphires, giving them a new, different color. At first they didnt know what had happened, but then they figured it out, and it became common practice for certain sapphires.

I guess that brings us to Songea sapphires. I read that these stones from a region of Africa would come out of the ground as unattractive rough, with poor color. But they used the Be heat method to "improve" the color of these so called Songea sapphires, and thats how we got these new color sapphires on the market.

They come in colors like pinkish-red, bright orange, deep golden yellow, etc. That brings me to question #1. With the pinkish red Songea sapphires, there were regularly these odd, black, ink-blot inclusions inside them! The funny thing was that these inclusions of that ink-blot style didnt show up in the other colored Songea sapphires, so the pink-ish red ones must be from another mine area than the other colored songea sapphires. I dont see those black spots in the orange ones or gold ones. Whats up with that?

That was a shame, because I thought the pinkish-red ones were by far the prettiest, but they usually had those obvious, ugly inclusions. So I bought a few fairly large orange and yellow ones at good prices, which are very clean. I have a 2ct orange, a 2.7ct orange, and a 3.7ct orange one. A few 1+ ct size yellows, as well as a couple natural yellows. I know they arent worth as much as either a heat-only sapphire or certainly not as much as a non-treated sapphire, but they were pretty cheap and nice looking, so.........

\What do you think of them, have you bought any, and how much are they worth? How stable are they, and is there any "special" treatment that they need in order to not be damaged? I know that the color is only "skin deep" with these things.....

 

[Pandora II]

The Be-diffused Pad stones hit the market in around 1999/2000 - I attended a lecture on them at the Vicenza Gold Fair in Sept 2001 as they were becoming a big issue for the market.

I haven't got time to check right now, but IIRC, it was Chrysoberyl that had been in the crucible before.

Initially the stones were only diffused skin deep, but now the diffusion penetrates the entire stone. It is a stable treatment.

The corundum is heated to just below melting point and this allows the beryllium atoms to enter the lattice structure of the crystal. Diffusion today also includes elements like titanium - used when diffusion blue sapphires.

I wouldn't buy Be stones for my collection, but I have them as study stones and I also have a lovely pair of pad earrings that I am 99% certain are diffused.

I certainly recommend them to people that want a great coloured stone in a big size at a very reasonable price - for example if I wanted to make a necklace with a 5ct ruby pendant, I couldn't begin to afford the $$$$$$$$$$$$$$ for a decent ruby that size - a Be treated stone will give me the effect I'm after at a fraction of the cost. I would probably prefer a Be diffused stone over a synthetic and it's a no brainer when it comes to lead-glass filled.

Value-wise they are extremely reasonable in price - not pennies, but very affordable. They don't hold value though - if you want to sell them then eBay is probably your best bet!

The biggest issue with Be is disclosure. Testing involves a very expensive machine (LA-ICP-MS is the best, but there are also LIBS and SIMS that are often used but are less accurate) which uses a laser to vaporise a series of spots on the stone, the vapour is then analysed to detect the elements present. It is not a cheap test by any means. Often there will be signs that a lab or gemmologist can see that will indicate probable diffusion - there are also signs that will indicate the stone has not been treated (very high heat is needed which will destroy natural inclusions such as rutile silk - which melts at around 1400 degrees C) and that further testing isn't required.

Unfortunately certain stones - some blue sapphires from Madagascar for example - that contain Beryllium naturally - although generally at lower levels. When it comes to Titanium diffusion, that is a real bugger as the chromophores in blue sapphire are iron and titanium to start with!

ETA: It's not just Songea - it's pretty much ALL of the types... Ceylon, Thai, Madagascan, Burmese, Kashmir, Australian - you name it, it gets treated (Montana is probably your safest bet).

 

[JewelFreak]

I don't know about blues, but here's an article (undated, annoying) that mentions Be-treating yellow Montanas. I suppose if they do it with them, there's no reason they wouldn't treat blue ones if the price they can ask makes it worthwhile. I'm sure smarter people here than I am know more.

http://www.modernjeweler.com/online/article.jsp?siteSection=1&id=375&pageNum=1



--- Laurie

 

[chrono]

Although this article was written in 2003, it still provides useful information about diffusion.
http://lgdl.gia.edu/pdfs/su03a1.pdf

Beryllium diffusion is done to improve all colours of corundum, turning almost colourless or pale corundum into stunning yellow and orange sapphires, pink sapphire into a “padparadscha” appearance or a vivid orange, as well as the conversion of bluish rubies to a fine red color. It also can reduce the amount of blue in dark blue sapphires, rendering them a more attractive colour. Not all sapphires treated with beryllium show an intense colour though, so a bright vivid coloured sapphire isn't the only suspect for diffusion.

There are many types of diffusion, begining with titanium where it produced a blue layer under the surface, called “surface diffusion” by some gemologists. If you cut into the stone, you can see this effect easily, where it shows the effect of the colour only on the outer rim. With Be diffusion, the induced colour layer penetrates deep into the stone, giving it a full and even colouration. Beryllium is introduced into corundum by adding chrysoberyl to the crucibles in which the stones are heated. As you can see in the many pictures in the article, sapphires from different locales in the world have been subjected to diffusion, not just Songea sapphires.

Be diffused stones can be identified by mass spectroscopy like SIMS analysis, LIBS and LA-ICP-MS but these technique is expensive and time consuming. Usually, the presence of certain inclusions is sufficient to prove a particular stone has not been exposed to the high heat temperatures required for diffusions and therefore could not be diffused.

1. CO2 Inclusions – Internal “voids” that contain water and a bubble of carbon dioxide (CO2) are quite common in sapphires from some localities, particularly Sri Lanka. Because CO2 expands when heated, these inclusions cannot survive the very high temperatures necessary for Be diffusion. Therefore, the presence of undamaged inclusions would prove that a stone has not been Be-diffusion treated.

2. Internal voids filled with other liquids will also not survive high-temperature heat treatment. The presence of undamaged liquid-filled voids of any kind proves that no Be treatment has occurred.

3. Included Crystals – The presence of undamaged zircon crystals in a sapphire is a good indication that Be diffusion treatment has not taken place. It is unlikely that any crystalline inclusion could survive the temperatures required for Be diffusion without being significantly
altered. Therefore, the presence of transparent, angular, or rounded solid grains of any mineral would be an excellent indication that Be diffusion has not taken place.

4. Rutile Needles – Needle-like inclusions of rutile, often referred to as “silk,” are common in corundum from many localities. These needles usually survive the lower-temperature heat treatments that are performed on some sapphires. However, they typically do not survive the higher-temperature treatments to which most blue sapphires and rubies are subjected, including the very high temperatures necessary for Be-diffusion treatment. The presence of unaltered rutile needles means that a stone has not been exposed to this (or any other) high-temperature treatment.

Diffused corundum is not affect by routine cleaning (steam and ultrasonic) and jewellery repair procedures. The treatment is stable and permanent. However, it is well known that the use of borax-containing chemicals (both fire coat and flux) contributes to moderate to severe surface etching of corundum. If etching due to exposure to borax-containing compounds is severe enough, the stone might
have to be repolished.

Transparent corundum is actually a common commodity. Only corundum in attractive colors and color saturation levels is rare. There are large deposits of sapphire that can produce large stones in unmarketable colors. Conventional heat treatment can improve only a very small percentage of such material. However, it appears that much, if not most, of this material can be Be diffused to produce
attractive colours.

I am not opposed to diffusion at all as long as it is disclosed and priced appropriately. As mentioned above, diffused corundum fits a different market niche that allows consumers to purchase a very attractive and large sapphire at low pricing. Personally, I do not collect any diffused stone because this treatment method is too invasive (it is essentially a dye job).


Pandora,
Isn't titanium diffusion easier to detect because it only affects the outer layer? Wouldn't immersion be all that is needed?

 

[LD]

Be treated sapphires have been around for years. Typically they are inexpensive and look very good. If you don't mind treatments then this is a very good stone to go for as the more modern diffusion is stable and right through the stone (as opposed to the older style that literally just coated the gems).

I have seen "rubies" treated with Be that rival some of the best rubies I've ever seen! Orange sapphires, yellow sapphires, blues, pinks etc., you name it! They come in all colours and if you look on Ebay the multi coloured bracelets (or loose stones to put into tennis style bracelets) are nearly all Be diffused.

The biggest issue I have is that this isn't routinely disclosed. In fact, it's a smaller proportion of vendors that disclose and that, to me, is very very very misleading.

I wouldn't touch them with a barge-pole. For me, this is man messing around too much with a natural product to produce something that is "fake" for want of a better word. However, that's my personal opinion and I have, in the past, recommended them to people who want a "look" and have a tight budget to work with.

 

[Pandora II]

Chrono - often immersion is enough, but nowadays it is becoming common to diffuse the preforms and not the cut stones - the spider-web is therefore much harder to spot.

The other thing is that much of the original treatment involved inexpensive stones of poor colour, today it's often a case of diffusing a $300 sapphire in order to obtain a $500 stone rather than diffusing a $5 to obtain a $200. So you are already starting with a decently coloured stone and the diffusion just fills in the zoning rather than trying to turn a pale stone blue.

In this situation it's far harder to spot the signs - especially if the stone has also been treated as a preform rather than cut.

 

[Arkteia]

So would the zoning, too, indicate lack of treatment? Let us say, there is a zoned sapphire without rutile in it to look at the threads and without chrystal inclusions? But you see the zoning? Would it be an indirect symptom of lack of treatment?

 

[chrono]

Arkteia,
I would not use zoning as proof of lack of treatment. Variations in trace-element concentrations can create the colour zoning typically seen in many natural sapphires, which makes accurate chemical analysis very laborious.

 

[Pandora II]

Presence of colour zoning is definitely NOT an indication of no treatment.

 

[RedSpinel]

When I read the info about Be treated Sapphires about 7 years ago, they made it out to seem that only the Songea sapphires were being Be treated to improve their dull color and add value where there previously was none.

I wasnt aware that they use Be and Ti treatments to make blue sapphires more or less blue, and to make less than ideal rubies more ideal.

The yellow Be sapphires I bought were purchased around 6-7 years ago and the larger orange ones were bought 4-5 years ago. So I dont know whether that puts them in the "newer" category of Be sapphires that are more deeply treated, instead of the older Be treated sapphires which the color was only surface deep(?)

I can understand why some people like LD dont desire to buy these due to their unnatural color that didnt exist until it was basically chemically "painted on". The way I look at it is that they might not be as desirable as a fully natural, or eat only sapphire, but they still are natural sapphires, minus the artificial color, and if they are pretty, bright, and most importantly cheap, then I'll put a few in my collection with the heat only sapphires I already had.

Plus, I used to go on the web, find nice looking gems for auction, and place low bids on MANY of them, then wait and see what would happen. I wouldnt bid them up any more, so I'd lose 98% of those auctions, but every once in a while, I'd win one cheap!

I paid $19 for my pretty, clean and bright 2.7ct orange sapphire, and $125 for my nice 3.7ct orange sapphire. Thats a total of $144. If I'd tried to buy both a 2.7ct and a 3.7ct clean sapphire, with heat only in canary yellow, I wouldve definitely paid MUCH more than $144....... So I'll stomach it as they are still sapphires with a hardness of 9. I wont be mounting them though.......

 

[ChrisA222]

I get what you are saying RS, but I am definately in the anti-BE camp. I'm also in the anti-synthetics camp as well. If I was OK with the fact that the stone was grown in a lab, I could have a ringstone with comparable looks to that beautiful sapphire that was recently posted in the 7 stone ring for probably 1% of the cost. Furthur, the stone would be 100% perfect..no inclusions...it would perform exactly the same..and, if it were precision cut, everyone would think I had THE best sapphire ever. But I would know..that it is something that was grown in a lab...it takes everything special away from the gem, in my opinion. Even though the gem looks the same, or better, it just did not come from nature and that is what is the appeal, for me. The same goes for BE...it came out of the ground looking like crud. It is crud. But painted crud. Man can create many beautiful things and thats fine..but something that came from nature like that??(the natural sapphire in the 7 stone ring post) Amazing, and thats why all of us collect gemstones.

What I don't get is all the crazy money spent on Moissanite. I was watching JTV one day, flipping through channels, and I saw a Moissanite they were selling for like $800??? For a stone that is grown in a lab?? I could never, ever understand why anybody would spend that kind of money on a created stone. I get that its pretty, but come on. I'd take that $800 and if I wanted the look of a Diamond, I would buy the best White Sapphire I could find, and I am sure I would find a nice one for $800. Or, a white zircon, or a Danburite, or whatever....a diamond that is less than ideal. Just my opinion....

 

[Pandora II]

I get what you are saying RS, but I am definately in the anti-BE camp. I'm also in the anti-synthetics camp as well. If I was OK with the fact that the stone was grown in a lab, I could have a ringstone with comparable looks to that beautiful sapphire that was recently posted in the 7 stone ring for probably 1% of the cost. Furthur, the stone would be 100% perfect..no inclusions...it would perform exactly the same..and, if it were precision cut, everyone would think I had THE best sapphire ever. But I would know..that it is something that was grown in a lab...it takes everything special away from the gem, in my opinion. Even though the gem looks the same, or better, it just did not come from nature and that is what is the appeal, for me. The same goes for BE...it came out of the ground looking like crud. It is crud. But painted crud. Man can create many beautiful things and thats fine..but something that came from nature like that??(the natural sapphire in the 7 stone ring post) Amazing, and thats why all of us collect gemstones.

What I don't get is all the crazy money spent on Moissanite. I was watching JTV one day, flipping through channels, and I saw a Moissanite they were selling for like $800??? For a stone that is grown in a lab?? I could never, ever understand why anybody would spend that kind of money on a created stone. I get that its pretty, but come on. I'd take that $800 and if I wanted the look of a Diamond, I would buy the best White Sapphire I could find, and I am sure I would find a nice one for $800. Or, a white zircon, or a Danburite, or whatever....a diamond that is less than ideal. Just my opinion....

Not true - many Be diffused sapphires actually look pretty good... they just look much better afterwards.

A $500/ct stone can become a $800/ct stone with an improved colour.

 

[chrono]

Some of the pre-diffused sapphires did indeed look like crud, but some weren't bad looking before at all. Remember, the intent is to get better pricing than what the original unenhanced corundum can sell for. As example, decent pinks were diffused to achieve the higher priced padparadscha sapphire.