I am a Hong Kong based professional gemstone supplier and GIA graduate gemologist. I specialise in rose cut cabochons as well as standard cabochons, and I have a carefully nurtured reputation for high quality. Currently I carry mainly semi-precious stones and I also have a range of pearls in white and natural colours; strings and half-drilled, round and keshi. This blog is attached to my website - www.joopygems.com - and is where you'll find information about new arrivals in my shop, discounts and offers, as well as an opportunity to leave comments and feedback.
Watermelon tourmalines classically mimic the fruit, with their juicy fruit and rind; bright pink in the middle, green on the outside. However, they come in so many different colours, representing the full spectrum of tourmaline’s impressive colour range. In fact tourmaline’s original name was ‘turamali’ which means ‘mixed colours’. It’s quite simply one of my favourite stones, but maybe not the easiest to set; it’s not always easy to find pairs and the profiles are often very uneven and bockety.
Tourmaline grows in pegmatites – veins that run through rocks created by molten magma from volcanoes. As the magma cools, cracks form which fill with a solution of water and minerals such as iron, lithium or manganese. Over thousands of years, these turn into tourmaline crystals, and it is depending on which of these minerals is present that determines the colour. So how do you end up with more than one colour in the same stone? This happens when the trace elements change in concentration or composition during a crystal’s growth. This can result in a core of one colour and bands of different colours, or zones across the length of the crystal. A single tourmaline crystal can contain up to 15 different colours. Tourmaline is the birthstone for October and I always think that is so lucky, as you have such a huge choice of colours. It is said to be particularly beneficial to artists and those in creative fields.
Watermelon tourmaline lends itself wonderfully to carvings – in particular butterfly wings and leaves look great, but arguably the best way to display it is quite simply, in slices, to show off its saturated juiciness to full effect. Although it can be prong-set, I love to see these slices in bezels, and I especially love Sarah Walker’s classic settings below. I haven’t seen slices set like this very often and I really like it. Links and titles on each photo.
I have a range of quality watermelon tourmaline slices, to take a look, click here
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.
Beryllium treated sapphire, photo GIA, Elizabeth Schrader
Two halves of the same sapphire; the left untreated, the right beryllium treated, photo credit GIA, Elizabeth Schrader
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
Actually, the green-eyed monster pretty perfectly describes my feelings whenever I see a piece of tsavorite garnet, whether it’s in jewellery or not. It’s my favourite green stone and I’m sorry, for my money, it beats emerald into a cocked hat. It’s bright green, extremely brilliant and unlike emerald, it’s not routinely treated. Tsavorite garnet, in case you don’t know is the transparent lime-green to emerald green variety of grossular garnet, and actually, the colour is due to the same minerals that colour emeralds – chromium or vanadium. A relative newcomer, it was discovered in the 1960s and is mined in Kenya and Tanzania. It’s hard to find in large sizes, in fact the finest emerald green colour rarely occurs in crystals larger than 2 carats, and so larger stones are therefore a great deal more expensive. Smaller stones are not too expensive, however, and in fact it works really well in pave settings as it is so brilliant.
For centuries, garnet has been thought of as a travellers stone; according to legend Noah’s ark was supposed to have a garnet lantern to help with navigation. In particular, garnet is supposed to promote strength, vitality and positivity, so you really can’t go wrong! We have tsavorite garnet rose cuts in small sizes – 2mm, 3mm and 4mm, starting from $4.25 for a 2mm stone, and I will be listing a few 5mm stones in the next few days. You can browse the collection by clicking here.
This is one of my favourite stones, and the most valuable of the red garnets. Rhodolite garnet has a colour range between pinkish red and deep raspberry pink and it’s not just a colour call that distinguishes it from other red garnets; it is to do with its composition. It’s a mixture of pyrope and almandine garnets, with its own distinctive refractive index, and it tends to come up a bit cleaner than almandine. Although its plentiful and reasonably priced, garnet does generally have a high specific gravity – what does this mean? It means that it’s dense and stones are relatively heavy for their size.
I’m always getting asked about birthstones, and so I finally thought it would make sense to make a section on my website for them. I started off quite ambitiously trying to include every system I could find, but that quickly got a bit complicated and, well, large. So I’ve stuck to modern British and USA systems. There’s a huge choice for every month and I’m looking to boost my selection of precious stones this year, so look out April, May, July and September birthdays! You can browse the selection in my new ‘Shop by Birthstone’ section.
What could I be talking about except garnet! You know what I mean; dull, rusty red stones set in gold-plated filligree. Nope. It’s just not fair. Garnet is one of the most exciting and varied of gemstones. It’s got a very wide colour-palette and price-wise it varies from the highly reasonable almandine to tsavorite at the top-end. It is also the birthstone for January.
Garnet has particular gemmological properties that make it reasonably straightforward to cut – it is what is known as singly refractive so what this means in real terms is that it is not at all pleochroic and therefore cutters don’t have to worry about what angle they are cutting it to make sure they are getting top colour. Many varieties also have a relatively high refractive index. What does this mean? Well, it is a measure of what happens when light hits a stone – a high index means that much of the light is reflected back to your eye; a low index means that much of the light passes right through. In real terms, stones with higher refractive indices are more sparkly. With the darker stones it’s not so obvious, but the sparkle on some tsavorites is simply amazing. See below and bottom for some examples of seriously stylish garnet jewellery.
Ananda Khalsa Garnet Stud Earrings with Two 22k Dots, $440
David J Thomas Tsavorite Garnet and 18k Gold Ring
Coffin and Trout Spessartite Garnet, Rubellite and 18K Gold Pendant
Red is the best-known colour of garnet, and the type that most people think of when they think of garnets is almandine. This commonly comes up very dark, what we call ‘closed’, and especially in larger sizes; however, it can be the most beautiful shade of deep blood-red. I have some almandine pears which just make me think of Sleeping Beauty every time I see them! In fact, the name ‘garnet’ comes from the Latin word ‘granatum’ which means ‘dark red’. Pyrope garnet is also red; you see it more rarely and it often has a slightly pinker note to it – it lacks the rustiness you can sometimes get with almandine. For a more pronounced pink colour there is rhodolite which ranges from pinkish red to a deep raspberry pink. For orange, there is hessonite, with its gorgeous swirling inclusions, and more expensively, spessartite. Malay garnet runs from yellow-orange to a lovely pinkish orange. Then you get the greens; hydrogrossular garnet with its black inclusions, yellowish-green demantoid with its horsetail inclusions, and vivid green, sparkling, firey grossular garnet, more commonly known as tsavorite. This is one of my favourite stones and I would take it over emerald any day. Garnet is also a really good choice for anyone who is not keen on gem treatments as it is not routinely treated with heat or anything else.
Jane Taylor Malay Garnet and 14k Gold Ring, $1200
Vintage Tsavorite Garnet & Diamond Invisible Set Cocktail Ring 14k Gold
Quadram Hexagon Almandine Garnet Ring, $1800
William White Hessonite Garnet and Sterling Silver Ring
Henn of London Spessartite Garnet and 18k Gold Necklace
Pantone has announced their colour of the year for 2019 and it is a bright orange-pink: ‘Living Coral’. From a jewellery perspective it’s a slightly awkward one, as the obvious stone, or rather mineral to represent this colour is, of course, coral. But coral has become a bit contraversial in recent years, due to environmental concerns around the depletion of coral reefs. In the past, red and pink coral was harvested in a completely unsustainable way from reefs in the Pacific, until the coral was all gone. So if you stock it, you want it to be sustainably sourced, but once it is on the market, it is almost impossible to know where it has come from. I’d like to stock this, but I think realistically, it’s not going to be possible. Alternatives in this colour range go from pale to deep orange; I’m thinking peach moonstone, pink pearls, padparadscha sapphire, morganite, conch pearls, fire opal, carnelian, tourmaline and rhodochrosite. I love both La Corser’s conch pearl necklace below paired with the the vibrant yellow diamonds and paraiaba tourmaline, and the softness of William White’s peach moonstone and prehnite combination. From left, clockwise, Turquoise and Sterling Silver Ring, Lia Chahla, Conch Pearl, Diamond and Tourmaline Necklace, La Corser Jewelry, Baroque Pearl Choker, Freshwater Creation, Peach Moonstone, Prehnite and 9k Gold Stacking Rings, William White, and Peach Tourmaline, 18k Gold and Sterling Silver Ring, Janish Jewels.
Turquoise and Sterling Silver Ring, Lia Chahla, $197
Conch Pearl, Diamond and Tourmaline Necklace, La Corser Jewelry, $2060
Peach Moonstone, Prehnite & 9ct Gold Ring, William White, $864
Coloured Pearl Choker, Freshwater Creation, $850
In terms of pairings for living coral, it’s tempting to look to the other brights on their colour report but I think that these will drown this colour. Personally I’m not fond of it paired with bright blues but turquoise and rhodochrosiste can be awfully pretty (see top left and top right). I think it does best when put with more subtle partners. Think peach and white, or peach and grey moonstone. Or as above, peach moonstone with the soft green of prehnite. Or peach pearls matched with white or rainbow moonstone. Or labradorite with any of these, which marries the the soft grey with a turquoise glow.
We have a selection of coral coloured stones; to shop the collection, click here.
It’s only relatively recently that black diamonds have become prized as gemstones in their own right. Traditionally either thrown away or used solely for industrial purposes, it’s really only in the past thirty or so years that they have come into their own. Now called ‘fancy blacks’, they began their popularity streak when designers started using them to contrast with colourless stones in pave settings and have got bigger and better ever since, in fact you might say they finally ‘arrived’ when Mr Big gave Carrie a 5 carat black diamond ring at the end of Sex and the City 2! Since then, there have been more high-profile black diamond engagement rings and of course, prices have risen in line with their popularity. They are unique stones, having the adamantine brilliance you’d expect from a diamond, despite the fact that they are black and opaque. They glitter, like mirrors, with a silvery lustre. Still, there are relatively few famous black diamonds, one of which is the Black Orlov which comes laden with the usual kind of myths and legends of curse and disaster.
But what is a black diamond? Conversations with customers over the years have told me that this gemstone is not well-understood. Natural black diamond is, in fact, simply diamond that is so included with mineral inclusions, such as haematite, pyrite and graphite that it appears black. It is also often criss-crossed with minute cleavages and fractures that are either stained black or have become black due to graphitisation (the formation of graphite due to a process too arcane for me to wrap my feeble head around). And in fact, a great deal of black diamond on the market is irradiated, so that the inclusions turn black. I always state the black diamond I sell as irradiated, as I am generally not sure and better to be safe than sorry…
The upshot of this is that black diamond is rather brittle, and it is this that causes confusion. Yes, diamond is hard; very hard. But hardness is not the same as toughness. Glass is hard but will shatter if you drop it; putty is soft but you can drop it and it will remain in one piece. Black diamond, filled with inclusions and riven with tiny fractures is pretty brittle. Don’t drop it, don’t – as a friend of mine did – slam it in a car door and do set it with care. You can also expect it to be rather prone to pitting, certainly on the base and around the girdle and often on the facets edges and corners. But if you can live with all that, you’ve got a gemstone like none other. Below, I love the contrast of the black and white diamonds, accentuated by the use of silver and oxidised metals in this Coco & Chia stacking ring set.
You can clearly see, top, the included nature of black diamonds in this beautiful rose cut black diamond ring from Lex Luxe – you can actually identify the blackened, frondlike clouds of inclusions. Another option from this jeweller is this black and white diamond cuff bracelet, with the contrasting colours offset by oxidised metal. And, right, just because it’s black, doesn’t have to go in white metal; this black diamond cluster ring (bottom) by Ferkos Fine Jewelry is set in 14k gold.
At Joopy Gems we carry rose cut black diamonds in a range from 3mm-5mm. These are sized pretty precisely as small differences make a disproportionate difference in terms of price when the carat price is high. The 3mm and 4mm stones are of slightly higher quality than the other sizes but you can expect the odd pit and fracture as is normal with this stone. To browse the entire range, click here.
A few years ago I started seeing Super 7 at gemstone fairs. I hadn’t seen it before and I first saw it on the stand of a really fantastic Brazilian gemstone supplier who always has the most sublime quality tourmaline and rutile. Gorgeous clear crystal with bronze coloured needles shot through with smears of bright purple. I had to ask what it was. Super 7, they said. Another gemstone that sounds like car wax (like chrome diopside in my view!). But there’s a really good reason for the name: Super 7 is made up of 7 different minerals. It’s a quartz base with goethite, cacoxenite, rutile, lepidocrocite, amethyst, clear quartz and smoky quartz included. Now this can make for a rather murky stone, however, the whole point of it, the ‘super’ part, the reason it is also called ‘sacred 7’, and referred to as ‘the healing stone’ is that this combination of 7 minerals are supposed to have powerful healing properties. For jewellery, it’s better that the inclusions are a bit more sparing and in fact, it can still be called Super 7 even if it does not include all 7 of the minerals. An awful lot of people have not heard of it, and I do think with such an unprepossessing name it may well stay that way. Names matter, and Super 7 just doesn’t resonate with most people. However, do take a look at it. At its best it’s really special. Below are a couple of really nice examples, both sterling silver and Super 7: left is by Doorways to Power and right by Divinity Jeweler
Divinity Jeweler Sterling Silver and Super 7 Pendant $277.72
Doorways to Power Sterling Silver and Super 7 Pendant $398
To view our collection of Super 7 cabochons, click here
I’m a bit late posting about my newsletter this month, but it is out, and I have a bunch of new things to offer you. Gorgeous carved flowers in mother of pearl and jade, rose cut ruby, rose cut black diamond, super 7 and some lovely rose cut green tourmaline, always thin on the ground and always very popular. There’s a newsletter exclusive offer this month too, so why not check out the newsletter and maybe sign up to make sure you’ll always get those offers first?! You can read the newsletter here, or sign up here