Gemological Association of New Zealand

Transcription

1 GANZ Committee Phone Hm Phone Wk President Jill Towers FGA DGA BSc d Lake Road, Takapuna, Auckland. Vice Pres Gavin Canty FGA Secretary Kathryn Barcham FGA Treasurer Donald Francey FGA PO Box 20, Shortland Street, Auckland Gemological Association of New Zealand Inc Committee Ian Bond FGA Paul Bunker GG Liz Carroll FGA Coralie Van Camp FGA Neil Hanna Volume 11 Issue 1 July 2010 Newsletter Editor Graeme Petersen FGA; 9 Innverness Drive, Pyes Pa, Tauranga 3112 Phone or ; carver.petersen@xtra.co.nz Would you call this a Ruby, see inside for more details!!! My first Spectra; a Flame Fusion Synthetic Ruby (editor Graeme Petersen) Volume 11 Issue 1 Page No 28 Newsletter of the Gemological Association of New Zealand

2 Editorial July 2010 Volume 11 Issue 1 Hi all Once again treatments and enhancements have kept the gemmologists of the world on their toes. Many sellers of gems that have enhancements seem to be very reluctant to give honest and true descriptions of the gems they have for sale, this is especially so on the major auction sites New Zealand s biggest auction site allows traders to describe them in virtually any way the like and at this time do not want to take any action to make these traders give accurate and true descriptions I am on a campaign to get traders selling their gems to give HON- EST and TRUE descriptions of their gems and I have some of the rip offs and dishonest descriptions in an article in this issue. Go and cruise the Trade Me site for gems, you will see Glass Filled Rubies being sold with the only enhancement listed as heating or synthetic Quartz being sold as Natural, obvious Diffusion Treated Sapphires being sold as heat treated. I do not have a problem with these items being sold on auction sites or anywhere, I do have a problem with the descriptions being supplied, some traders have a disclaimer saying they don t know or cannot afford to have their gems tested, this is totally UNACCEPT- ABLE, jewellery shops, genuine gem merchants cannot do this, so how come auction sites allow this!!! Their excuse is that because of specialist nature of the types of items being listed makes it very difficult for their staff to confirm whether products are accurately described or not. Further as a vendor, they do not take an active part in the listing process and do not take possession of the goods nor do they pre-screen listings. (try listing a fridge or a car with an incorrect description and they soon pounce on you) As always my I deeply indebted and my heartfelt thanks to Bear Williams, Wolf Kuhen and others who supply me items and or allow me to reproduce their work for our newsletter If you see or have an item of interest please let me know Cheers Graeme Petersen FGA (editor) with spectrometers of other manufacturers. Measurements: 65 x 50 x 27 mm; weight 70 gr; spectral range nm The portable GL Gem Spectrometer system includes attachable GL Halogen 10W Gem light holder, fiber probe (1 m laboratory grade UV-VIS), USB cable, 12 V power adaptor, software PLEASE NOTE: The spectrometer requires a USB port (no separate drivers necessary, USB 2.0/HID 1.0 compliant). The software package contains the GLGemSpec program (WinNT/2000/XP/ Vista/Win 7 and LINUX/Mac OSX (tested with wine and MacOS inside Virtual- Box); also provided is a runtime package for LabView 7.1 (for developers the VIs for LabView version 7.1 and 2009 are provided). The Quick Manual explains the setup and operation of the spectrometer system but provides only sample spectra for demonstration purposes. It is hoped that users of the GLGemSpec system will help to build up an expansive spectra database which will be made available on-line. Future upgrades to the GLGemSpec program can be down-loaded free. This spectrometer can be order direct form the CIG The total cost including freight is approx NZ$2,400 depending on the exchange rate NZ v Canadian $ Here is the link Order now on-line at GL Gem Spectrometer System Editors Note: My Spectrometer has arrived and I have it up and running it certainly is a wonderful addition to my instruments, easy to set up and get going. I recommend this to all of you. I will also be doing a full review of it in a future issue of our newsletter, if anyone would like more details please feel free to contact me (details on back page of newsletter) Graeme Petersen F.G.A. Volume 11 Issue 1 Page No 2 27

3 Specifications of the GL Gem Spectrometer Weight: 430 grams Dimensions: 102 mm x 84 mm x 59 mm Detector:Toshiba: TCD1304AP linear array Detector range: nm Pixels: 3648 Pixel size: 8 mm x200 mm Signal-to-noise ratio:300:1 A/D resolution:14 bit Fiber optic connector: SMA 905 to 0.22 numerical aperture single-strand optical fiber Wavelength and Optical resolution: nm < 1 nm (with 50 um slit) Exposure time: 2.5 ms-10 s CCD reading time: 14 ms Data transfer speed: 200 ms / 100 ms (2 points binding) Power consumption: 5V from computer interface: USB 2.0, HID 2.0 (USB cable included) Operational system: Windows 98/ Me/XP/Vista/Windows 7 and others Specifications of the GL Halogen 10W light source and gem holder GL Halogen 10W light holder with built-in cosine corrector, cooling fan, includes 12V power adaptor (12 V battery optional, underneath spectrometer) for portable use with laptop computer. The holder has a SMA 905 coupler and is easily unmounted from the spectrometer; it can be connected and used Volume 11 Issue 1 Page No 26 Inside this issue: India s Diamond History Auction Rip Off s LED s the way of the future GL Gem Spectrometer Special points of interest: New Spectrometer now available at a very reasonable Price from the Canadian Institute of Gemmology India s Diamond Mining History & Diamond Mining Active & Inactive Reprinted from India's Diamonds of Golconda Diamonds were discovered in India during the 4th century B.C., and India was one of the first countries to mine the gem. India's diamonds were prized for their size and beauty for hundreds of years. "Indian" diamonds were mined in numerous locations that included Borneo (Landak), Golconda, Hindostan, and Raolconda. The majority of India and Borneo's diamond deposits were alluvial as opposed to Kimberlite. India's most prized diamonds are known as the "diamonds of Golconda," and the most famous Golconda stones include the Hope Diamond, Koh-I-Noor Diamond, Orlov Diamond, and Sanc Diamond. The Darya-i-Nur (Sea of Light) was a rare blue-diamond weighed 186 carats, which was owned by the Nadir Shah of Persia after it was plundered from the last 'Great Mughal Emperor,' Aurangzeb's heirs in the 'sack of Delhi' in Geology 'Golconda' diamonds found on the Indian subcontinent, were created from the enormous forces generated by the 'Tethys Oceanic Crust' colliding, and being subducted under the 'Asian Continental plate' (aka plate tectonics). Although these massive continental plates collided at the incredibly slow rate of 10 centimetres per year, this was enough force over 100s of millions of years, to create the Himalayan Mountain range, and to cause the necessary volcanic activity to create diamondiferous intrusive and extrusive igneous rock known as 'kimberlite.' Millions of years of erosion caused by rainfall and snowmelt, unearthed the diamonds from their kimberlite source, and washed them downstream to their final

4 it is 35%, around 1000 nm it is 45% (with averaged efficiency for both polarizations around 55%). That is better than other units costing twice as much. Also important is a proper light source though the GLGemSpec can be used with the fiber alone; spectroscopists often develop their own setup depending on the material and the type of measurement. For gemstone analysis a tungsten halogen light source, a xenon light, various types of lasers resting place in the alluvial river gravels of the 'Golconda' region. Golconda (golkunda) was a region located between the lower reaches of the Godavari and Krishna rivers, in the present-day state of Andhra Pradesh, central India (map above). Today, the exact source of the 'lost mines of Golconda' are unknown, and the India's only remaining diamond source is the Majhgawan pipe near Panna (see:" Mining in India Today" below). Diamonds are inextricably woven into the cultural fabric and mysticism of Buddhism, Hinduism, and Tibetan Lamaism. The 'dorjes' is an ancient Buddhist talisman shaped like a pyramidal four-faceted diamond representing the sacred mountain of Mount Meru at the 'center of the universe.' Portuguese Church in Old Goa The 'Valley of Diamonds' No doubt, many a young lad was drawn to India and the Far East, by tales of adventure and riches beyond one's wildest dreams. The tales of Sinbad and the 'Arabian Nights', were derived from an 8th century Sassanid Persian book called Hazar Afsanah or "Thousand Myths." and UV-LEDs are being used. The GL Halogen 10W is a basic light source with built-in cosine corrector, cooling fan, gem positioner and is mounted directly onto the spectrometer; it can also be used with spectrometers of other manufacturers. The GL Gem Spectrometer is a USB 2.0/HID compliant device and does not need a soft-ware driver as many other spectrometers do; the GLGemSpec software is simple to install (only 104 KB; it would work on an old laptop running Windows 98), easy to learn and extremely fast in obtaining and saving spectras. They can be imported into other software such as the highly recommended Spekwin32 spectroscopy software which allows for quick viewing, comparison and documentation of a project; we also provide LabView users with VIs for further development on their platforms. Acknowledgements: I would like to thank Martin Haske at Adamas Gemological Laboratory for his extensive research and contribution in making spectrophotometers accessible to gemmologists. I hope that the GL Gem Spectroscope with its low acquisition cost will make this technology available to many more. Volume 11 Issue 1 Page No 4 25

5 Blue nm, Orange nm, Green nm, Red nm, also Infra Red LED s 850nm and 940nm I have been trying to source LED s in the SWUV area but to date those that are available are very expensive, (US$250 each) so at this time it is still best to work with the original Fluorescent Lamp I will be doing further testing on these once I have them up and running I will report on the effects they have on various gems in later issues of our newsletter In the 'Second Voyage of Sinbad,' he was transported by a giant bird (roc), to a land where the floor of the valley is "carpeted with diamonds." Merchants harvest the diamonds by throwing chunks of meat into the valley, where the birds carry them back to their nest, ladened with diamonds. Sinbad straps one of the pieces of meat to his back, and returns to Baghdad with a fortune in diamonds. GL Gem Spectrometer System Wolf Kuehn of the Canadian Institute of Gemmology (CIG) has produced a new Instrument which should be a must on all Gemmologists lists of instruments to have The CIG offer this economically prized and very efficient spectrometer package for the experienced gemmologist. Over the last 3 years they have tested several spectrometers and numerous soft-ware packages. The high price of commercial systems excluded many gemmologists from owning and operating such a valuable tool. Portable GL Gem Spectrometer with attached miniature GLHalogen 10W light holder with battery pack connected to Dell Mini 9" laptop Volume 11 Issue 1 Page No 24 With the help of a local engineer they have custom designed a broad band gem spectrometer which is affordable and highly sensitive. It uses a back illuminated CCD sensor; the software compensates for etalation in the near IR. Our diffraction grating efficiency is optimized for 500 nm (see specifications below); at 300nm Goa's Diamond Trade Route Most of the diamonds entering Europe originated in India. In the later half of the 14th century, the diamond trade route extended from India to Bruges, Paris and eventually to the Diamond Bourses of Antwerp, Belgium. After Portuguese explorer Bartolomeu Dias' 1488 discovery of the 'Cape of Good Hope' on Africa's southern most tip, fellow Portuguese navigator Vasco da Gama discovered a sea route to the India and Orient by sailing around the Cape in This provided Europeans with an easier route to the Indian diamond trade, avoiding the costly and dangerous 'Silk Road' caravan routes. Along India's Malabar Coast, the state of 'Goa' grew into a Portuguese trading center, and a diamond-trading route was established from Goa to Lisbon, Portugal and on to Antwerp. In 1510, the Portuguese established a permanent settlement in Velha Goa (Old Goa), after Portuguese admiral, Afonso de Albuquerque defeated the ruling Bijapur kings. The city of 'Vasco,' named after Vasco-da-Gama, is the state of Goa's largest city. Jean Baptiste Tavernier's "The Six Voyages" (Les Six Voyages) written in 1679 documented his extensive travels throughout India and the Far-East, in order to expand the trade in gems, jewellery, and other valuable commodities. In 'The Six Voyages', Tavernier meticulously illustrated many notable Indian diamond cuts. Diamond #1 (above, right) is the "Great Mogul Diamond" and Diamond #3 is the "Great Table Diamond". India was the only major producer of diamonds until the discovery of diamonds in South Africa in Shortly thereafter the De Beers Diamond 5

6 Company was founded by Cecil Rhodes Mining in India Today India is no longer a source for rough diamonds. Although most all of India's diamond mines were depleted centuries ago, there is one active diamond mine at Panna in the central Indian state of Madhya Pradesh (above, right). The mine is owned by the National Mineral Development Corporation. De Beers India is currently prospecting in the Madhya Pradesh region as well as in the southern Indian states of Andhra Pradesh, Chattisgarh, Karnataka, and Tamil Nadu. The De Beers mining operation will be a joint venture with Hindustan Diamond, be based in Mumbai. The Descriptive Term 'Golconda' The term 'Golconda' is still used (or misused) today as an indicator of very high quality diamonds. To justify the 'Golconda' name, diamonds must have a level of transparency and quality found only in rare, chemically pure type-iia natural diamonds. The term 'Golconda' is also used as a generic term to describe higher quality diamonds with an antique cut. Volume 11 Issue 1 Page No 6 Synthetic Ruby Ring using 400nm Torch 23 With mercury UV tubes we could see things that were not visible with incandesce light bulbs. Now with LED light we can generate exclusive wave lengths that the older tubes cannot. While it is not the purpose of the author to dispute the validity of current or past UV light sources, there is a definite and pressing need for the industry to set new and accurate gemmological standards based on better technology, with which we can begin to compile a new body of reference data. Further information added by the Editor Graeme E. Petersen F.G.A. I have a torch that I have had the white LED s replaced with Yellow (see photo above) and as suggested by Bear, this makes an excellent monochromatic Synthetic Blue Spinel in natural light source of light for taking very accurate refractive index readings. The conversion was done for me by LED Stuff in Dunedin I suggest you check out their web site for details of LED lighting here is the link I also have an LED torch with 400nm LED s, this is an excellent and quick test for The same Synthetic Blue Spinel under the many gems. 400nm UV torch (I am selling these at $15 each contact me if you would like one) See photos of the use of this torch, very quick and effective test LED Stuff in Dunedin are very helpful when it comes to the supply of special need torches or LED lighting, they are converting more torches for me with the following LED s;

7 as we re-equip ourselves during the 21 st century. We need a pure SW UV energy source, and Sensor Electronics in Columbia, SC, utilizes nitride technology to produce SW UV LEDS that are available from 247 to 365nm in 5mm increments These emit in the same clean emission as the above pictured hand lights. Keep in mind that all LED light sources have well defined wavelengths. Since we have established the SW designation at 254nm, then we could obtain similar results with a single source LED at 255nm. NTT Basic Research Labs, in Asugi, Japan, has created aluminium nitride LEDS that produce a far UV (2l0nm) radiation. This can well open great potential in gemmological research. In her paper "LED Light Sources for Gemmologists," Sylvia Gumpsberger notes that due to the nature of the tighter wavelengths the white LED sources are not suitable if you are using it for the spectroscope or other full spectrum needs. Currently, the manufacturers are looking for methods of broadening the spectrum on the whites. Also of note is the use of the yellow LED, which gives a good monochromatic source that is excellent for refractive index readings. If you are thinking of updating your laboratory with the latest technology, you can expect different results than the textbooks and you will not be wrong. It is not just UV LEDS that we can benefit from. As previously mentioned, blue lights can give us fluorescence through crossed filters, but many of these light ranges that are in the violet to ultra violet, specifically in the nm range, can give surprising results. These penlight style LW UV LED lights are readily available in today's market and have no problem fitting in a pocket. They are being discovered in a variety of retail locations. The sub-uv ranges in wavelength induce strong fluorescence even in stones previously thought inert to fluorescence, like garnets. A large variety of different garnet species like Spessartite, Malaya, and Tsavorite have proven to fluoresce very nicely when using a 402nm LED. Oddly enough, fluorescence in some garnet is overlooked because they fluoresce in their own body colour. Yellow LED torch with LED used to convert Active Diamond Mines Currently there are eleven major 'diamond producing' nations, and a host of other counties with operational and/or historic alluvial, open pit, and hard rock diamond mines. There are also several African nations with ongoing off-shore dredging/vacuming operations. Africa Angola 1. Catoca Diamond Mine: Fourth largest diamond mine in world. Kimberlite pipe. 2. Fucauma Diamond Mine: Newly constructed. Owned by Endiama (40%) & Trans Hex (35%). 3. Luarica Diamond Mine: Owned by Endiama (38%) & Trans Hex (32%). 4. Luzamba Diamond Mine: Angola's largest alluvial mine, Endiama (50%), Odebrecht (50%). Botswana 1. Damtshaa Diamond Mine: (water for a tortoise) New open pit mine. De Beers / Botswana. 2. Jwaneng Diamond Mine: (place of small stones) richest mine in world. De Beers/Botswana. 3. Letlhakane Diamond Mine: ("little reeds") second oldest of four - De Beers / Botswana. 4. Orapa Diamond Mine: (resting place for lions) Largest/oldest of four - DeBeers/Botswana. Congo (DROC or RDC) 1. Bakwanga Mine: (aka Bushimaïe, Lubilash) Alluvial river mines in Kasaï. MIBA. 2. Forminière Diamond Mine: Alluvial mine located on the River Tshikapa, in Kasaï - closed. Namibia 1. Elizabeth Bay Mine: Open-cast mine in Namib desert, south of Lüderitz. Namdeb. 2. Orange River (Daberas) Mines: Orange River alluvium. Namdeb Volume 11 Issue 1 Page No 22 7

8 Namib Gov. 3. Marine Mining: Namco Mining operates a dredging fleet off the west coast of Namibia. Sierra Leone 1. Magna Egoli Mine: Largest mechanized mine in Sierra Leone. Waldman Resources, Israel. 2. Koidu-Sefadu Mines: Subsistence digging in alluvium pits west of Koidu. 3. Koidu Open Pit Mines: Kimberlite open-pit mines just south of Koidu. South Africa 1. Baken Diamond Mine: Located along Orange River in North Cape, So Africa. Trans Hex. 2. Cullinan Diamond Mine: Open Pit/Hard Rock diamond mine owned by De Beers. 3. Finsch Diamond Mine: Finsch is an open-pit mine near Lime Acres, De Beers operated. 4. Kimberley Diamond Mine: Started in 1871, the Kimberley Open Pits closed in Koffiefontein Diamond Mine: The Koffiefontein mine opened in Closed in The Oaks Diamond Mine: In Limpopo province. Open-pit mine De Beers operated. 7. Venetia Diamond Mine: Limpopo, produces over 40% of world's gem-quality diamonds. Tanzania 1. Williamson Diamond Mine: (aka Mwadui mine) Open Pit mine. 75% De Beers ownership Zimbabwe 1. Murowa Diamond Mine: Open Pit & Underground mine. 75% De Beers ownership. River Ranch Diamond Mine: Open Pit & Underground mine. 75% De Beers ownership. Volume 11 Issue 1 Page No 8 Show Your True Colours bleed and confuse our readings. 21 that different illuminants can greatly increase the value of fluorescence in diagnostic testing. When considering this and the Hoover-Theisen ex/em models, all authors note that the longer the wavelength of excitation light used, the stronger the emission Gemmologist Sylvia Gumpsberger of the Canadian Gemmological Association even uses various red light sources for her fluorescence observations As gemmologists we rely on our eyes for observing visible fluorescence. What then is the best energy source to use? No need to deal with a SW UV if its only going to have a secondary energy Why not a purer energy source that is quick and easy to use, as can be provided by light-emitting diode (LED) technology? Pictured are a variety of commonly available LED light sources (Figure 6) that range from 392 to 645nm. From left to right in the accompanying graph (Figure 7) you can see their emissions superimposed as overlays according to their light colour. Is there bleed or extraneous illumination caused by LEDS? No, each produces a singular, pure light range. lt will inevitably be what we want to use in all our future gemmological testing. As an example, we may note something like; "The stone did not 255nm, but showed a whitish yellow at 365nm and a bright orange at 404nm." This may be the first step for our gemmological community to discuss in their varied standardization group meetings

9 emission, please draw your attention to the 365nm line simultaneously emitting. This line is a LW componecnt. Though it is only half the amplitude of the 254nm line, its existence there could lead to what is often interpreted as the stone being weakly fluorescing in SW when in fact it is probably induced by the leaking LW component There is no need to be vague with this. We can see the need to precisely identify the source of energy that is causing the excitation. lt may be called SW or LW but when they have several energy levels that bleed or overlap each other as we have plainly seen, it is not an exact science. ln multiple tests made in various jewellers gem labs, all the U V lights tested as having the LW UV bleeding through their SW tube style testing lights. Solutions are on the horizon, but first let us discuss some basics Stokes Law Fluorescence begins when the absorption of visible or UV radiation raises the atoms to an excited state. The electrons absorb this quantum energy and jump to a higher energy orbit. The subsequent return of these electrons to their ground orbit is when the energy is released as radiation, mostly as visible light or near infrared. According to Stokes law, this emission occurs at a longer wavelength (lower energy level) than the energy source used to excite the stone. A very interesting study using excitation and their respective emissions was performed (Hoover & Theisen, 1993) that gave a gradation of energy sources ranging from nm in 5nm increments and their emission responses. This was laid out in a 3D graph and the interesting fact that many gems have little if any response whatsoever to UV radiation of wavelengths shorter than 300nm, most being inert to shorter wavelengths. Again we see the need for proper definition of energy source to fluorescent reaction, especially since most of the excitation occurred from visible light ranges The graph shows the excitation wave length and the resulting emissions of a natural Alexandrite. Some Alternatives and Solutions Crossed filters, a technique for observing fluorescence introduced by Basal Anderson, uses a visible blue light source without the need for UV. In various testing it is noted that even slight variations in energy levels (392nm vs. 404nm) significantly affect the luminescent response. This is where and how we can make our fluorescence readings a more exact science. Harding (1994) and Hoover-Williams (2005) in "Crossed Filters Revisited caution in their observations Volume 11 Issue 1 Page No 20 Australia East Kimberley 1. Argyle Diamond Mine: Largest producer in world, mostly industrial grade. Rio Tinto. Borneo Cempaka/Riam Kanan, South Kalimantan 1. Cempaka Diamond Mines: Alluvials mined by indigenous artisanal Kalimantan miners. Canada North West Territories (NWT) 1. Diavik Diamond Mine: The Diavik diamond mine is located in the NWT. 2. Ekati Diamond Mine: Canada's first diamond mining operation, located in NWT. India Madhya Pradesh 1. Panna Diamond Mine: Alluvial mine in state of Madhya Pradesh. Russia Siberia 1. Aikhal GOK Mine: Three open-pit kimberlite pipe mines: Aikhal, Jubilee, and Sytykan. 2. Anabar GOK Mine: The northern most location of Russia's diamond mines. 3. Jubilee (Yubileinaya) Mine: Newer open-pit kimberlite mine near Udachny. Alrosa. 4. Mirna Mine: Largest diamond deposit in Russia and one of the largest in the world. 5. Udachnaya (Udachny) Pipe Mine: One of the deepest diamond mines in the world. Inactive (Historical) Diamond Mines There are hundreds of inactive historical diamond mines scattered 9

10 throughout the world. This list contains the most historically significant mines. Australia 1. Merlin Diamond Mine: Kimberlite pit located in Northern Territory. Inactive. Borneo 1. Landak Diamond Mines: Alluvial deposits along Landak and Kapuas river. extinguished. Tanjungpura (?) Diamond Mines: Alluvial deposits in the Banjarmasin basin. extinguished Brazil Bahia 1. Serra de Chapada: Alluvial deposits that are mined out. Now a national park. 2. Salobro: Alluvial deposits along the Pardo river. 3. Serra de Cincora: Alluvial deposits & carbonado at Paraguassu river, richest in Bahia. 4. Sincorá Range: Alluvial deposits in 'Tombador Formation' sandstones and conglomerates. Mato Grosso 1. Cachoueira Du Pau: Alluvial river-bank deposits. New explorations taking place. 2. Melgueira: Alluvial river-bank deposits. New explorations taking place. 3. Rio Pires: Alluvial river-bank deposits. 4. Rio Sonho Azul: Alluvial river-bank deposits. 5. Tres Barras: Alluvial river-bank deposits. New explorations taking place. Mato Grosso Do Sul 1. Riberao Varadouro: Alluvial river-bank deposits. 2. Rio Coxim: Alluvial river-bank deposits. Volume 11 Issue 1 Page No 10 band. 19 see some problems that arise. Using a UV-Vis spectrophotometer, you can see the mercury spectrum (Fig 2) of a LW-UV light source. ln this graph we can readily see the 365nm line, which is the designated emission for the LW-UV However, upon closer examination it is apparent that other, longer wavelengths are also emitted by most of these types of bulbs. Since other energy is present which energy is truly activating the fluorescence for a particular stone? Not necessarily the sole designated 365nm line and quite probably the other mercury lines at 404 and 435nm wavelengths. These other wavelength bleeds are not a bad thing in themselves. In fact, the nm excitations are fantastic energy sources to induce fluorescence, but not if you are under the impression that it is the 365nm energy that is doing it, and not if you are comparing results with someone who has a pure 365nm source. Looking at the second graph (Figure 3) we see a very troubling anomaly with these bulbs. The visible results are readily apparent and in the SW mode we see its 254nme emmission peak. While the 254nm is the designated

11 LED s the way of the Future By Bear Williams This article and photos and has reproduced from a paper originally Published in The Gem Guide Jan/Feb 2007 with permission of Bear Williams and added to by Graeme Petersen Bear Williams is a GIA graduate and the owner and lab director of Stone Group Labs. He and his partner Cara Williams enjoy researching the many unexplored aspects of gemmology and bringing the science of gemmology up to date. Bear is a member of ICA, serving as cochairman of the GILC, and as a director of the AGTA he chairs the Gemmological & Industry Rules Committee. Ultraviolet light sources for testing gem fluorescence have been a staple piece of gem equipment for decades Emerging technologies will not only change the way you look at ultraviolet but could well eventually redefine our industry standards When a gemmologist is ready to test for UV fluorescence, they usually reach for their ultraviolet (UV) light. Most of these lamps (Figure I) will have two buttons for switching between long-wave (LW) and short-wave (SW). The bulb inside this device is a low pressure mercury tube, developed in You are possibly reading this article by an over head fluorescent light right now. These standard, overhead low-pressure tubes are coated on the inside with powdered phosphors that react to the electrical discharge and emit the white light that we observe. On the other hand, the UV bulb, also a low pressure mercury tube, is coated with nickel oxides to block out the visible wavelengths. Filtering out longer wave lengths in the nanometer (nm) visible ranges allows only the higher energy LW and SW UV luminescence This "black light" technology saw its main production begin in the late 1920's. But what could be wrong with this technology as it applies to gemmology? If we take a look at the emissions in these type of bulbs one can 3. Rio Piquiri: Alluvial river-bank deposits. 4. Rio Taquari Mirim: Alluvial river-bank deposits. Minas Gerais 1. Rio Abaete: Alluvial river-bank deposits, mined from 1785 to 1807, now mined out. 2. Rio Bagagem: Alluvial river-bank deposits. 3. Campo Do Sampaio: Alluvial river-bank deposits. 4. Colinas: Alluvial river-bank deposits. 5. Fazenda Velha: Alluvial river-bank deposits. 6. Rio Dourados: Alluvial river-bank deposits. 7. Rio Preto: Alluvial river-bank deposits. 8. Santa Maria: Alluvial river-bank deposits. 9. Serrinha: Alluvial river-bank deposits. Rondônia Unknown: Alluvial river-bank deposits. India Golconda Diamond Mines: Alluvial deposits, Godavari, Krishna rivers in Andhra Pradesh. Venezuela Bolivar 1. Capaura: Placer Deposits 2. Chiricayen Mine: Placer Deposits 3. El Resbalon Del Diablo Mine: 4. La Hoya Mine: United States Arkansas Crater of Diamonds Mine: An Arkansas State Park located in Murfreesboro, Arkansas. Volume 11 Issue 1 Page No 18 11

12 Auction Rip Offs and Scams What the General Public Don t know By Graeme E Petersen F.G.A ct; 23 x 19mm Syn Quartz; Ametrine Purple & Yellow Do you have some synthetic stones or lead glass filled rubies, or diffuse treated sapphires to sell? If so list them on one of our New Zealand auction sites, on our leading auction site you don t have to give an honest description, just list them with any kind of description at all, you can of course put in a disclaimer that these stones are not tested or that you rely on the person you bought them from as to what they are, and to stop negative feedback you can say if they do not turn out to be what you said you will give a full refund The auction sites don t check what you say, so go ahead list what you have and plead ignorance as to what it really is I have a nice collection of lead glass filled rubies, synthetic quartz, diffuse treated sapphires all bought from Trade Me, in every case the description was not correct. Following are some of what I have purchased and the descriptions given by the seller. Judge for yourself Stone No 1 Full of Lead Glass but described by the seller as Heat Treated, no mention of any filling, my question re filling went unanswered by the seller $1 RE 11.05CT GIANT REAL RICH RED PINK RUBY $5517 So if you have any odd stones that you want to quit, put them on one of our auction sites, you can describe them how you like, put any kind of disclaimer you want, and if they turn out to be not what they are described as; you can always offer a refund to the purchaser. I personally don t have a problem with Synthetic, glass filled, or any treated stones being sold on auction sites as long as they are described correctly. These sites should be held to task about items listed on their sites, unfortunately they accept no responsibility for the accuracy of the descriptions given ITEM DESCRIPTION PRODUCT NAME RUBY (NATURAL) UNIT OF ITEM (S) 1 PIECE. WEIGHT (CT.) CT. DIMENSION 16.8 X 12.0 X 7.0 MM. SHAPE/CUT PEAR FACET COLOR AAA RICH RED PINK CLARITY/GRADE TRANSPARENT & TRANSLUCENT LUSTER GORGEOUS Volume 11 Issue 1 Page No 12 17

13 tor! This would make a unique present for someone born in July. Or, perhaps you deserve a prezzie for yourself to celebrate something? As the photo shows, it is in a very attractive oval cut and is a beautiful and prized pigeon blood red in colour. It is 33.5 x 24 x 8mm in size - an extremely large and rare 66.5cwt size for a precious ruby gemstone. Priced at just $1 per carat. This is a ridiculous price for a genuine ruby don't you think? My Guarantee of Quality I only buy from suppliers with an established (5+ years) and good reputation so I stand behind what I sell and will refund in full (or replace at our discretion) if items are defective or not as described. Questions and answers This stone looks to be lead glass filled, if you say not, have you had it tested? 6:27 pm, Tue 23 Feb Hi there, given the low pricing, it would be far too expensive to have all these stones tested. 9:28 pm, Tue 23 Feb I have since purchased from legitimate dealers several stones for comparison, they are 3 very nice Synthetic Quartz stones; here are some photos of them 1: an identical stone to the Blue and Yellow one listed in this article 2; a nice green and lemon synthetic 3; an ametrine showing purple and yellow All of these are Synthetic Hydrothermal Quartz TREATMENT HEATED ORIGIN MOZAMBIQUE HARDNESS 9 PLEASE NOTE: WE BUY OUR STONES FROM REPUTED SUPPLIERS AND WE DON'T TEST STONES FROM OUR END AS IT IS VERY EXPENSIVE AND WE CAN- NOT AFFORD TO TEST ALL THE STONES AND SELL IT AT THE PRICE WE DO, WE TOTALLY RELY ON OUR SUPPLIER'S DESCRIPTION GIVEN TO US. IF U PUR- CHASE STONES FROM US YOU CAN GET IT TESTED AND IF THE STONE IS NOT AS DESCRIBED AS ON OUR AUCTIONS THEN WE OFFER A 100% REFUND ON ALL OUR STONES. As none of my stones have been tested in New Zealand, any treatment, or grading given to the stone cannot be confirmed unless sent to a Lab for inspection by a trained gemmologist in NEW ZEALAND. Questions and answers Many rubies are lead glass filled, that make them very fragile and susceptible to heat, ultrasonic cleaning, has this stone been lead glass filled?? 8:01 pm, Sat 20 Feb I did ask a question about lead glass filling but as you can see it remained unanswered, The stone is full of Lead Glass, and how they could come up with a value of $5,517 is beyond me, but of course it can be sent back for a refund, how many retail shops or genuine Gem Merchants would sell a gemstone with this sort of disclaimer Stone No 2 A synthetic bi Colour Quart being sold as a Natural Ct. PHENOMENAL BI COLOR GOLDEN BLUE CITRINE Product Description 9.98ct; 16 x 12mm Syn Quartz; Blue & Yell Volume 11 Issue 1 Page No ct; 20 x 15mm Syn Quartz; Green & Yellow Quantity : 1 Piece (s) Gem type : Citrine Weight : Ct. Size : 20.8 x 15.5 x 12.4 mm. Colour : Bi Colour Golden Blue Shape : Emerald Cut Clarity : VVS 13

14 Lustre : Very Good Origin : Brazil Treatment : HEATED Hardness : 7 PLEASE READ THE AUCTION AND ITS DESCRIPTION IN FULL AND THEN BID, IF U DO NOT UNDERSTAND ANYTHING PLEASE DO NOT HESITATE TO ASK ANY QUESTIONS. PLEASE NOTE: WE BUY OUR STONES AND JEWELLERY FROM REPUTED SUPPLI- ERS AND WE DON'T TEST STONES OR JEWELLERY FROM OUR END AS IT IS VERY EXPENSIVE AND WE CANNOT AFFORD TO TEST EVERY THE STONE AND JEWEL- LERY AND SELL IT AT THE PRICE WE DO, WE TOTALLY RELY ON OUR SUP- PLIER'S DESCRIPTION GIVEN TO US. IF U PURCHASE STONES OR JEWELLERY FROM US, YOU CAN GET IT TESTED AND IF THE STONE OR JEWELLERY IS NOT AS DESCRIBED AS ON OUR AUCTIONS THEN WE OFFER A 100% REFUND ON ALL OUR STONES. As none of our stones and jewellery have been tested in New Zealand, any treatment, or grading given to the stone or jewellery cannot be confirmed unless sent to a Lab for inspection by a trained gemmologist in NEW ZEALAND. Please remember to contact us if there are any grievances with the product before placing your feedback and we will definitely try to resolve the issue. This looks like a synthetic Quartz are you sure it is natural???? 7:56 pm, Sat 20 Feb Hello There, This is a Natural Stone. Thanks 8:00 pm, Sat 20 Feb Once again I asked a question, as to if the was synthetic and NO it was not, I was assured it was a NATURAL STONE. Indications of synthetic are small breadcrumb inclusions, also one sure indication of natural is Brazil Twinning, well surprise, surprise microscopic inspection revealed some bread crumb inclusions and no Brazil Twinning some very nice interference colours but NO Brazil Twinning Stone No 3 This one is a beauty, a supposed Genuine Ruby This material usually starts off as African Purplish colour Corundum with heavy lamellar twinning, inclusions and intergrowth and basal parting planes. It is processed and then acid bathed to remove a lot of the other minerals. Then the heat delivery of either flux type healing or lead glass filling takes place to clarify and often colour enhance the product. In other words JUNK. It should in reality be described as Hybrid-Ruby, Glass Filled Composite, requires Special Care Bi Colour Quartz through Crossed Polars, no sign of any twinning Questions and answers Bi Colour Quartz, showing distinct Bread crumb like inclusions Lovely HUGE *66+cwt* Faceted Genuine Ruby Gemstone Start price: $66.50 Listing #: All purchases totalling over $ will receive a beautiful genuine Egyptian perfume bottle absolutely free!!! These fabulous bottles are hand blown and highly decorated with 24ct yellow gold. The photo in my profile shows a selection of the types of bottles that will be given away in this promotion. This stunning genuine ruby gemstone is a very big stone perfect for setting as a big impact pendant, probably too big for a ring - there is nothing like the buzz of having a particularly nice/unusual gemstone set into your own design. It's also a beautiful example of a blood red ruby gemstone colour for a collec- Volume 11 Issue 1 Page No 14 15