Gem treatments have become ubiquitous in recent years. So many stones are treated, heated or fracture-filled; pearls are bleached, jade and turquoise is stabilised. It’s a thing that a some people react against, instinctively put off by the idea of it, as if it detracts from the stone. I’ve often encouraged people to not think of it like that; instead think more of how wood might be waxed or oiled, to bring out its natural beauty. Having said that, not all treatments are equal and we are now at the stage where the gem and jewellery industry has laid down clear guidelines and boundaries as to what is acceptable and what is not. For example, the industry accepts heat treatment of sapphire and ruby, to improve the colour. It accepts fracture filling of emerald, as emerald is such a brittle, fractured stone, whereby the oil filling helps to make the fractures less obvious. It accepts the stabilisation of turquoise whereby these soft stones are infused with wax or resin to make them harder, more durable and better able to take a polish. Certainly untreated stones will always attract a higher price than treated, but these treatments are accepted, as long as they are disclosed. However, there are many treatments that are considered much more controversial, for example the glass filling of rubies and bleaching and dyeing of jade. Anything, really, that results from the taking of very low quality rough and making it appear much, much better than it really is. BE treatment, or beryllium treatment of sapphire is one such treatment, and it has become so ubiquitous in coloured sapphire that many reputable dealers are simply not supplying coloured sapphire.
What is it?
Beryllium treatment is a form of lattice diffusion treatment. Such treatment, previously known as surface diffusion, or bulk diffusion involves the super-heating of pale, colourless, poorly coloured or even dark material in the presence of other elements. Titanium diffused sapphire has been around for a while, and in fact is rather easy to spot. It penetrates only the very surface of the stone and if you look at it under a microscope it is easy to see colour concentrations along facet edges. It’s a problem as it can easily be removed with repolishing. However in the early 2000s, many people began to become concerned at an influx of very intensely coloured sapphires onto the market; mainly in the pink-orange spectrum – stones that were like the very expensive padparadscha sapphires. The stones had been trading for at least 6 months before suspicions began to crystallise enough for serious detective work to begin.
The main problem was that the gem treaters denied strongly that anything new had been introduced. The GIA dedicated a huge amount of time to running their own experiments and concluded that these gems had been heated in the presence of beryllium. The treatment was a form of lattice diffusion, but unlike with titanium diffused stones, the colour penetrates a great deal further and sometimes right through the stones. This makes it much harder to detect. The process introduces yellow, orange and brown components into stones, which results in bright yellow and orange colours from pale corundum, the alteration of pink sapphire to padparadscha, the conversion of bluish ruby to a fine red, and it can also reduce dark tones in blue sapphire to make it a better blue. Initially they faced continuing denial from the gem treaters but through a series of their own experiments they were able to reproduce all of the colours that had been seen and considered suspect on the market. In 2003 the Chanthaburi Gem and Jewelry Association finally admitted to the practice.
Why is it a problem?
The issue is that it taking poor or low quality material and by infusing another chemical and heating to just below the melting point of the stone is considered crossing a line. It goes beyond enhancement as it alters the chemical state of the stone and to put it bluntly, attempts to make a silk purse out of a sow’s ear. What is the problem with that? Well some might say, what’s the issue if the treatment is disclosed? It results in lower-priced stones, and as long as everyone knows what they are getting, what is the problem? The trouble is that the treatment is very hard to detect. It cannot be detected using any standard gemmological treatments and in fact there are only a few gemmological laboratories in the world that can detect the treatment, as it requires a particular kind of laser treatment in order to take samples of the material and test it (LIBS (Laser Induced Breakdown Spectrometer) and LA-ICP-MS (Laser Ablation Inductively Couple Plasma Mass Spectrometer). Labs that do not have the equipment will often state on their reports ‘not LIBS tested’. The issue is not confined therefore to dishonest dealers, but since gems change hands so many times between mine and final customer, information might be lost along the way. You might end up with BE stones without realising it. The person who sold them to you might not realise it. The person who sold them to you might not understand the issues and importance of disclosing it and simply fail to mention it. Someone who doesn’t know much about gemstones might pick up a BE treated stone on their travels, think ‘oh what a bargain’ and then sell it on as if it were not treated, because they simply don’t know that they don’t have a bargain, they have a stone that is worth less than it looks. Once a stone is set, it is hard to evaluate it anyway, and someone who has bought a piece of jewellery may fail to mention it if they sell it on, or give it or bequeath it.
So how do you know?
As I’ve mentioned, it is extremely hard to detect this treatment, and requires specialist gemmological equipment for a definite diagnosis. However, there are indications to the treatment that can be made with standard equipment and a bit of common-sense.
- Price: The most obvious one. Pay attention to the standard advice: if it looks too good to be true, it probably is. BE treated sapphires cost a great deal less than untreated stones, so be suspicious of any stones that seem a great deal cheaper than they should be
- Colour: BE treatment results in very intense colours. Intense orange and yellow sapphire is very rare in nature so if you are seeing a lot of stones like this, it may be an indication that it is BE treated. This is not definitive as sapphire occurs in all colours, including bright yellow and orange. But if it is natural, it is rare, and it ought therefore to be very expensive. Some reports have estimated that most of the yellow and orange sapphire on the market is now BE treated, so some suppliers (myself included) simply do not touch any of it. Better to be safe than sorry.
- Microscope inclusions: with this treatment, corundum is treated to close to its melting point. Normally with heating, you can see evidence in mineral inclusions in the stone, eg halo fractures. With BE treatment, these inclusions will look destroyed; crystal forms turned into irregular masses, often with a crackled appearance and a gas bubble in the centre. This has not been observed with standard heating so it’s a good indication that BE treatment has taken place. You also might see synthetic crystal over-growth on the stone.
- ‘Rims’ or ‘rinds’ on the stone. You’ll need a liquid called methylene iodide, but if you immerse a BE treated stone in this, you’ll often see a different coloured rim or rind on the stone. However depending on how deeply the beryllium has penetrated the stone, it may not always be obvious. So whilst if you do see it, you can be pretty sure that the stone has been BE treated, its absence does not prove no BE
If you come across any of these indicators, especially if you are buying a large, expensive stone, it is imperative to get a full appraisal from a qualified lab.
Proceed with caution. BE treatment has been implicated in most colours of corundum. Check carefully on the descriptions of all stones you are buying, and ask about BE treatment before buying. I have seen it noted on some websites as ‘Be heated’ under treatment, and no, this is not just rubbish English, it indicates BE treatment. I think it is misleading as I am sure that many people see that and think it indicates simply that the stone is heated. Buying from a large, reputable dealer is important, as even with their small stones that are not worth enough to warrant an individual appraisal report, they will periodically test their rough to check it is not BE treated. I source my stones from such a supplier, and they have told me they stock no coloured sapphire, as so much of it is BE treated, it often comes mixed in with untreated material in the bags of rough, and so to be safe, they do not stock it at all. Although BE treatment has been used for blue sapphire, it is far less common and my supplier has not yet detected it in any of the rough they have bought. For this reason, I will be supplying no coloured sapphire in my store. To shop my range, click here
There are many articles discussing beryllium sapphire. For a rather technical, but highly interesting account (just skip the more technical parts if you can’t get your head round it!) of the history of beryllium sapphire and the detective work required to identify it, the 2003 GIA article, ‘Beryllium Diffusion of Ruby and Sapphire’ by Emmett et al is a great place to start.