Introducing my advent offer: every day – or more like every other day as I am so turned around with time zone differences, I’m struggling to work out for myself when things should end and begin – I’ll be posting an offer. Each one time limited. I’m posting each offer on my website, Facebook and Instagram, so you can keep updated by checking there, and also I’ll be sending some (although maybe not all as I don’t want to drive people crazy!) via my newsletter. You can see what’s on today by visiting joopygems.com
The first thing I am going to say is that pearls are treated, most of them, in one way or another. Let’s just get that out of the way. Even the most beautiful and expensive South Sea and Akoya pearls are likely to have some kinds of bleaching and for the pearls that I sell, they are definitely bleached. Let’s just have a brief walk-through the pearl landscape as it were. Most expensive and desirable are natural saltwater pearls; now extremely rare. It was the main source of wealth and the Arabian Gulf until the 1950s; of course once oil was discovered, pearls were eclipsed and in fact, many of the ancient pearl beds were torn up and destroyed. Most saltwater pearls are now cultured, and tend to come from the same sort of places that natural ones came from; for example Myanmar, China, Australia, French Polynesia and Africa to name a few. I deal mainly in cultured freshwater pearls; grown mainly in China on pearl farms; this is a very established industry that can yield very beautiful and affordable pearls. Even with these, there is huge variation with the very cheap, quickly-grown potato pearls competing with slower grown, more lustrous varieties.
Today I’m looking at peacock pearls. Natural black, South Sea or Tahtian pearls have a satiny, rather than high, lustre. With a dark green-grey body colour and a purple, pink, blue or gold overtone that appears to float on the surface of the pearl as the light catches it, these are magical, mysterious, iridescent pearls. These are beautiful and eye-wateringly expensive.
It’s not surprising, then, that artificial colour treatments have been developed, and this is what I want to talk about today. Treated peacock pearls are usually first soaked in silver nitrate (the same chemical that makes photographic film sensitive), then either exposed to light or hydrogen sulphide gas. This turns the pearls black. They are then dyed to achieve the colourful characteristic overtones. How do you tell them apart from the real thing? As with most things, if they look too good to be true, they probably are. That, and price. If the lustre is too high, the colours too bright, they are probably dyed. Size is another; South Sea and Tahitian pearls don’t normally come in sizes below 8mm – anything smaller than that and you are probably dealing with a treated pearl. It goes without saying that this should be stated, and I wouldn’t personally even describe a pearl as ‘like South Sea’ or ‘like Tahitian’ due to the potential for confusion. However, if you do want your treated peacocks to look a bit more like the real thing, then there are a few simple rules:
Step away from the lustre. As stated, real South Sea pearls have a satiny lustre; the high, almost metallic lustre is something that you might see on the banded Tahitian varieties, but generally, look for less lustrous pearls
Colour. The colours of treated peacock pearls are vibrant and beautiful, but to get a more authentic appearance, go for pearls that have more of a subtle colouring, with a more grey and less black body-colour
This is why I’m particularly excited about the 8mm half-drilled peacock pearls I have just listed, as they do fulfill both of these criteria. Not that I’m for a minute suggesting that you pass them off as real, just that if you are looking for a more authentic, less ‘oil-on-water’ appearance, these are a really good option; a lovely grey body-colour with subtle overtone. Check them out here.
A Note on Pearl Grading
Pearls is a funny business. Every time I shop, I have to reinvent the wheel, as just because one company had beautiful pearls a year ago, doesn’t mean that they will next time they restock. Another thing you have to realise is that there is no standardisation in terms of quality grading. A pearl company will sort its pearls in terms of the qualities that they hold, and so one company’s AAA is another’s AA and so on. Also – and this is a really funny one – AAA+ is less good than AAA. Just so you know. For me, there is nothing that takes the place of painstakingly going round suppliers and carefully comparing by eye to get the best quality for the price you want.
Actually it’s not raining here but it is rather overcast. And citrine has long be treasured as a gift from the sun. Natural citrine is pretty rare, although it does exist, and ranges from pale straw to deep amber. Generally the darker the colour, the more expensive it is. Madeira citrine, for example, is a beautiful, deep brandy colour, you can see the difference in William White’s Citrine Double Trillion ring below. This goes for treated citrine as well, and really a lot of citrine on the market is treated. Let’s just get that out of the way right now – it’s heated amethyst. It’s fairly safe to assume that most of the citrine you come across is going to be treated, and it’s fine, it’s an accepted treatment, but as always, with treatments it does need to be disclosed. The good thing is that this ensures there is a plentiful supply and therefore it remains affordable even in large sizes.
Citrine takes its name from the Latin ‘citrus’ and the French ‘citron’ – fairly self-explanatory, meaning lemon. It is said to carry the power of the sun giving strength, warmth, energy and pleasure. Its last period of real popularity was in the 1940s, set with stones like ruby, peridot and aquamarine in colourful pieces. Now, I think it’s pretty underrated, and there are plenty of people who would agree – here’s Brittany Siminitz at JCK news making a plea for the stone If you think it’s just for cheap birthstone jewellery, take a look at any of the pieces on this page. It even cropped up in Wallis Simpson’s iconic Cartier Flamingo Brooch. Below is a cocktail ring from Laing Antiques and Wallis’ iconic piece
It really pops with white metals, whilst yellow metal settings amplify and deepen its warmth and vibrancy, as can be seen in this beautiful, undulating de Grisogono ring below.
Citrine is a quartz, so it’s pretty durable at Mohs 7 making it a versatile stone that can be used in a number of different kinds of jewellery. We carry a variety of sizes and shapes at Joopy Gems, you can shop them here.
My November newsletter is out and it’s full of news, views and gemstone goodness. There’s a free ship offer for November as well as the last gasp of my bead sale and de-stash open for a limited stint. You can read it here. Newsletter readers are always the first to hear about offers, some of which are exclusive; why not sign up at joopygems.com?
Clarity’s a simply enough concept, right? A stone is clean or not and it’s clarity is described in neat categories. Well, no, not really. Diamonds are one thing, with the scale running from Flawless to Included, but the similarly categorised scale for coloured gems is a bit more complicated. And if you think about it for one second, this makes perfect sense. Because with diamonds, clarity is a huge value-factor. It has to be accurate, reliable and valid. It has to be able to be taught so that everyone grading the stones is doing roughly the same thing. But coloured stones are different, and one of the biggest ways they differ is in terms of their clarity types. This is a system of classification developed by the GIA to describe the way in which some stones, above and beyond the level of clarity of an individual stone, are basically more included than others. It divides stones into 3 types, and each clarity grade means something different for each type. It goes like this:
Type I Stones:
Stones that are usually eye-clean. For example, aquamarine, chrysoberyl, smoky quartz and blue zircon (there are others). These are stones that it’s not hard to find in clean quality, and for these, a VS stone means an eye-clean stone with inclusions that can be seen under 10x magnification.
Type II Stones:
These are stones that are usually included. For example, corundum, garnet, iolite, peridot, tourmaline, amethyst. These are stones that will usually have some degree of inclusion, and for these, and a VS stone will likely have noticeable inclusions under 10x magnification and these may well be eye-visible.
Type III Stones:
These stones are almost always included, and yes emerald, I’m talking about you. Because it’s hard to find clean crystals the standards for a VS stone are pretty low and so a VS type III stone will have obvious inclusions at 10x magnification which will be likely eye-visible. Such stones are, yes, emerald and the red and pink tourmalines. As well as red beryl, not that we are likely to come across a lot of that!
All of this ought to be obvious, but I am aware that when we talk about stones, we get hung up on things like clarity and grades, whilst forgetting that sometimes clean stones are just not realistic. Stones are natural, they come out of the ground. The marks and trauma within tell the story of their birth. All of this should be celebrated and there’s a place for every kind of stone, however included. As with everything, information and disclosure is the key.
Below you can see how beautiful included stones can be. On the left is a ring made from a tourmaline bought by a customer. This was made by Custom Jewelry Co in Australia. This is an included tourmaline but it’s just beautiful, like a map of the world.
I do periodically write about this issue as I am not convinced that – even though the practice has been around for a while – it is yet common knowledge. In short, glass filling is the practice of fracture-filling rubies with lead glass to improve their appearance. I’m going to lay it on the line, folks: this is bad. It takes poor quality, fractured material and turns it into pretty looking transparent red. It looks good but it is complete junk. Worse than that, it is no longer a ruby.
What is the treatment?
Fracture-filling is not new; emeralds have been fracture-filled with oil for years, and it is a completely accepted treatment. The idea being that you find a filler with the same or similar refractive index as the stone and the appearance of fractures are minimised. With emeralds this is fine, as oil is used, which can be removed if necessary and the stones re-oiled; in addition, the original material is usually reasonable. With rubies, the practice of lead glass filling takes rough that is opaque or near opaque – material that would otherwise be unsaleable – and permanently filling it with lead glass. Poor quality corundum is soaked in acid to remove mineral inclusions leaving a weakened and brittle stone; a stone so weak in fact that you could crumble it to powder with your hands. These skeletons are then infused with lead glass, which makes the stone stronger and prettier. The results are actually extraordinary: opaque corundum can be turned into stones with high transparency. So what’s the problem?
The Problems with Glass Filling
There are three main problems: firstly it is an extremely unstable treatment, secondly – and rather crucially – once a ruby has been glass filled it is no longer a ruby and thirdly, it is frequently not disclosed. Let’s take these one by one:
The GIA reports describe glass filled rubies like this: ‘ A manufactured product consisting of lead glass and ruby…unstable to high temperatures and to chemical agents.’ This says it all. The treatment is extremely unstable. Heat during jewelry making or repair will ruin it. Pickle to remove fire-scale will ruin it. Even the wearer can ruin it – most household cleaners will ruin it. Lemon juice will ruin it.
The stones are not rubies. They are ruby and glass composites and in many cases will be more glass than ruby.
The treatment is not disclosed. Sometimes this is blatant fraud; sellers will blatantly charge ruby price for something that is effectively worthless. I have suppliers who say they are finding glass filled rough in with the decent stuff. But most of the time it’s happening because people simply don’t know. They go to a show and buy a ruby and think, ‘oh I got a great deal’ and then sell the stone in jewellery as ruby. Sometimes even the big stores are selling these items undisclosed and, since I’m sure these stores don’t want to wreck their reputations, it must be that they simply don’t know what they are selling. From my own experience, I myself have found at gem fairs that when I’ve asked, ‘is this glass filled?’ that sellers have readily told me. But I have not been convinced that they would have done so, had I not asked.
This is really important, because the retailer is completely liable, whether the mistake is deliberate or accidental, they can be sued for not disclosing this treatment.
How is it detected?
Well, the good news is that unlike other nefarious treatments, this one is really easy to spot under magnification. A microscope or even a loupe will show up low relief fractures, gas bubbles (as is really common with glass), voids, and a yellow and blue flash effect. Failing this, one of the easiest ways – in my experience from attending gem fairs – is simply looking at the price: if it looks too good to be true, it probably is. That is, if you are looking at near-transparent ruby for a few dollars a carat, it’s probably glass-filled. This is fine if you know what you’re buying and for some reason you want ruby coloured glass – the danger comes if someone thinks they’ve got a great deal, and sell the stone on as ruby.
What’s the take-home message?
I’m not pulling punches with this because it really is complete rubbish. If you buy it and sell it on you are liable. There are also reports that it is being seen in sapphire as well as ruby, although the ruby composites are completely ubiquitous. Always, always ask, if you are buying a ruby. First question: ‘is it glass filled?’ In my experience, you will be told. Carry a loupe and learn how to use it. It’s not even always deliberate fraud; sometimes the sellers themselves don’t know what they’ve got on their hands. And remember, forewarned is forearmed.
What a lovely sounding title. If there is one thing that people generally want to avoid in gemstones, it’s a fracture or a feather; whether the crack is surface reaching or completely included in the stone, there’s always the danger of it opening up and splitting or at least weakening the stone. More than that, it’s unlikely that it’s ever going to actively add to a stone’s beauty. However, it’s such a common feature of stones, and indeed sometimes an integral part of the stone’s make-up that it bears closer inspection. A fracture can tell you how the stone was formed, give you information about whether and how it’s been treated
The first thing to be said is that all fractures are not equal. There is a difference between a large, unsightly feather right under the table of a diamond and a delicate fingerprint pattern inside a ruby. In addition, some types of stone are much more likely than others to be fractured in the first place. Let’s find out where they come from and in what forms you might find them.
Where do they come from?
During crystal growth; a result of internal tensions caused by structural defects or tectonic activity
During crystal growth; an integral part of the stone’s make up – eg parting in labradorite, cleavage etc
Whilst formed crystals are in the host rock, due to changes of pressure or mechanical damage produced by tectonic activity.
Secondary deposits, when gems are transported and accumulated, eg after being tumbled and washed down a stream.
In primary deposits, during mining or the recovery process (blasting and crushing of the rock).
During cutting itself: sawing, cutting and polishing, accidental blows or if internal tensions release, or if the stone becomes too hot.
In some treatments, due to thermal shock
During heating, included crystals inside the host crystal can expand leading to ‘halo fractures’
For mechanical reasons during jewelry making or repair process, eg setting
Once in jewellery, normal wear and tear, for example accidental bumps and abrasions
Large fractures in stone varieties known for easy cleavage; tanzanite, kyanite or topaz for example should be avoided. They don’t look good and worse, will seriously impact the durability of the stone. Any blow or accidental damage could cause the fracture to open up. As stone-cutter Meg Berry states, she likes to apply the ‘rule of thumb’ when it comes to fractures in stones; namely, if you can snap it with your thumb, you probably ought to. Smaller fractures are a different matter; some milky aquamarine is full of fractures and beautiful, watermelon tourmaline tends to come up quite fractured and of course with emerald it’s almost impossible to avoid. Below, the aquamarine is crazed with tiny fractures, but it adds to the density of the colour and the movement of the cut. The tourmaline slice is imperfect but the colours are still bright and the emerald looks like a planet, with its visible fractures and liquid inclusions.
It’s hard to think of any situation where a large inclusion adds to the beauty of a stone but as I was writing this I thought, if there’s one thing I’ve learned in 10 years in this business and that is that people are endlessly creative and can conjure beauty from the most unprepossessing of raw materials. Enter Jamie Johnson, and her Golden Joinery collection. These are all one of a kind; broken stones set in sterling silver with the seams of both cracked halves dipped in 22k gold. They are absolutely stunning. Below from left Aussie Boulder Opal Joinery Ring, $2860, Golden Joinery Turquoise Earrings, $2330 (photos courtesy of New Twist), Pendant necklace in oxidized sterling silver with 22k gold and rainbow moonstone, $2,970 and finally the group at the bottom featuring turquoise, ruby, boulder opal and green tourmaline (photos courtesy of David Wentworth at Flutter Studios). Aren’t these amazing?
Ah yes, labradorite. Think of labradorite and in your mind’s eye you’ll no doubt think of a multi-veined stone with the characteristic flash. Years ago I was having trouble with customers sending back stones because not only is the stone soft, but there’s a thing called lamellar twinning. Also known as ‘repeated’ or ‘multiple’ twinning, this results in the layered make up of the stone, which makes it prone to fracturing along these twin planes. It is also, however this make-up which gives rise to the flash – it is the light refracting off these planes that results in the characteristic labradorescence. So when customers tell me they want great flash and no fractures, I kind of want to throw my hands in the air and shriek!! However, I have now done my best with it; not entirely fracture-free but my labradorite is less fractured than most. I try to buy the translucent material with the superior flash, and that way I have happier customers and fewer returns. Even so, you’ll see in the picture below that there are still fracture lines across the stones. It’s pretty much unavoidable.
Cleavage is the tendancy of a crystal to break along distinct planes, and some stones are more prone than others, depending on their specific characteristics. It’s where the atomic bonds are weaker, so the crystal can split easily along those lines. Some have no cleavage – eg quartz, opal, agate, turquoise, ruby and sapphire, and some have perfect cleavage along one or more planes, for example topaz, diamond, kyanite, and all feldspars. It’s more of an issue during cutting – and in fact it used to be used to divide large gem crystals. Now cutters make sure that they cut such stones to minimise the chance of the stone cleaving during setting.
So we have seen that fractures have a function and a place. They may even be beautiful, and certainly they are sometimes unavoidable. I think I ‘ve gone on enough so next time we will be looking at other kinds of fracture – eg halos and fingerprints and also clarity types: the tendancy of some stones to be more included than others.
Aquamarine is a really great choice of stone; it’s pretty gemmy without being insanely expensive, it cuts well and takes a really high polish. In its transparent form, it’s more pricey but I just love the milky variety; in lovely shades of pale blue to sea-green, it is misty, hazy and dreamy. It’s common to find this material full of fractures and veils, but when it comes clean with a lovely translucency it is a beautiful, glowing stone. It is named after seawater itself: aqua = water and marina = of the sea and it is in fact a form of beryl, the same mineral as emerald. Unlike emerald, it grows in large and frequently clean crystals so it’s relatively easy to find it in large sizes and in fact can be exceptionally clean. Top colour is a moderately strong blue to greenish-blue. It’s a great jewellery stone and versatile as it’s also exceptionally hard – so a good option for a ring stone. The gemstone for March, aquamarine is offer protection in battle and make the wearer unconquerable; what more could you want! Clockwise from left below: CJ Bijoux aquamarine and 18k gold ring, AF Thomas aquamarine, blue topaz and 18k white gold ring, Gemory Design aquamarine and sterling silver ring and Gems Berry aquamarine and sterling silver ring
We sell a variety of really gorgeous, translucent aquamarine in cabochons and rose cuts as well as rose cut freeforms. To check them out, click here
Many years ago, shortly after I started out, the price of prehnite went shooting up. It was one of those odd things, where I had to do a bit of a double take. What could be going on? I was told, it was because it was being used as a jade substitute for the Chinese market. I did another double take, because I just couldn’t see it. Prehnite is so commonly pale, fractured, full of wisps and veils that I just couldn’t see how it could possibly substitute for jade. And then they brought out the good stuff; deep green, clean and glowing with an unearthly, dreamlike lustre. Ever since, I’ve tried to stock the better stuff, because when prehnite is good, it’s very, very good indeed. You might never even have heard of it. The GIA thinks not, as they have included it in their ‘Hot Gemstones’ round-up, but that makes it an excellent choice as you are not likely to run into it in your local jewellers. It’s a bit different, unusual and the prices (except for the really fine stuff) are pretty sensible. For meaning, it is best known as the stone of unconditional love, said to connect the head to the heart. It’s found mainly in Australia, Canada, China and the USA, and it’s a good choice for anyone who likes their stones untreated as it never is.
I’ve decided to do a series of posts on inclusions, as it is simply one of the most frequent topics that comes up with customers. Everyone knows the value of a nice, clean gemstone: no-one wants a diamond with a dirty great fracture, or a ruby with a big black crystal under the table. However, the search for a perfectly clean stone is a bit of a fool’s errand. The GIA no longer uses the term ‘internally flawless’ to describe diamonds as there is simply no such thing; with increasingly powerful microscopes, if you magnify anything enough times, you will find something. But above all, I think we need to reconsider attitudes to inclusions. The GIA doesn’t call them inclusions; preferring the term ‘clarity characteristics’, and if you believe that the very words we use are instrumental in influencing how people feel about a thing then we can see that this is a much less judgemental term to use. They describe clarity characteristics in a stone as ‘the eyewitnesses to its birth’. They can provide valuable information as to how and where it grew, indicate events in its history and sometimes on a broader scale, in the the events and internal turmoil of earth’s history. They can help detect whether a stone is natural or synthetic and provide evidence as to whether the stone has been treated or not. They almost always tell a story. And if you’ve ever held a pile of synthetic rubies in your hand you might find yourself thinking, as I have, that stones without inclusions can have all the appeal of a piece of coloured glass.
Golden Rutilated Quartz Cabochon Freesize, 41.975 carats, 29.8×21.5×9.6mm, $138.40
Golden Rutilated Quartz Cabochon Freesize, 9.65 carats, 16.1×12.1×7.2mm, $31.85
Inclusions are not always bad, either, and that’s my subject today. Sometimes they have a beneficial effect on a stone’s beauty, and that is certainly the case with needles! Needles are defined as long, thin, solid crystals or hollow tubes; if it’s hollow it might be filled with fluid or gas. A group of fine needles is called ‘silk’. Silk is what gives high quality sapphires their soft, velvety appearance, and can give rise to cat’s eyes and stars, if it is oriented along the stone’s crystal planes. Needles to me are at their best when they are present as visible needles in stones such as quartz and prehnite. These stones are desirable precisely because of their inclusions. In quartz, rutile needles can appear gold, copper, red and black. They can occur sparsely or in clumps; they can be thick and coarse, or they can be fine, the so-called angel-hair variety. You can also get rutilated prehnite; a soft, green bodycolour intersected with striking black needles. When we talk about inclusions it’s easy to see this as always having a negative connotation but it simply isn’t so. Rutilated stones really need only a simple, beautiful setting to show them off to their best, however, I love the setting below, where the design on the body of the ring echoes the spokes of the rutile in the quartz.
To shop our collection of rutilated stones, please click here. Next time I’ll be talking about the dreaded fractures!