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FANCY VIVID YELLOW DIAMOND
JANUS JEWELS – HOME OF BEAUTIFUL STONES
Janus Jewels specialises in old stones and the finest coloured stones. Every gemstone we handle is responsibly sourced, offered with impeccable provenance, and backed by appropriate certification and thorough due diligence. As our client, you can buy with confidence and sell with discretion, supported by clear advice on quality, value and timing.
Janus Jewels’ Founder and Managing Director, John C. Kulukundis, has an absolute passion for beautiful stones. A Graduate Gemmologist and Fellow of The Gemmological Association of Great Britain (Gem-A), he brings expert knowledge backed by decades of hands-on experience, including many years as International Jewellery Specialist for the world-renowned auctioneers Phillips.
A PASSION FOR STONES
RECENT ACQUISITIONS INCLUDE
Fancy Vivid Yellow, emerald cut diamond, 11.25 carats
Pigeon Blood, cushion shaped Burmese Ruby, 5.65 carats.
Untreated, oval cushion shaped Colombian Emerald, 4.1 carats
Electric blue, emerald cut, unheated Brazilian Paraiba Tourmaline, 3.6 carats.
A wide selection of extremely Fine White Diamonds.
GEMSTONES: WHAT DEFINES EXCELLENCE?
A jewel’s beauty and worth are traditionally judged by the familiar measures of carat (weight), colour (intensity or absence), clarity, and cut. But at Janus Jewels, we look beyond the conventional checklist. For us, a truly exceptional gem, whether loose or set, has a unique, unforgettable character.
Exciting jewels are alive with stories to tell
“I’ve handled many magnificent and important jewels, but there is so much more to a great stone than simply carat and cost: the finest have a life of their own. Although not always the largest or most expensive, they have, without exception, the power to captivate.”
JOHN C. KULUKUNDIS
Exciting jewels are alive with stories to tell
"For me, the finest gems are not necessarily the most expensive. However, without exception, they have the power to bewitch and beguile. Whether a remarkably rare Old Mine Kashmir sapphire or a gorgeous, rich Siberian amethyst, every stone Janus Jewels handles has that special quality."
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FANCY VIVID PINK DIAMOND
WHAT IS A RARE GEMSTONE?
The term ‘rare’ is often misused in today’s jewellery trade to describe high-value stones. But a genuinely rare gemstone is one that’s scarcely found in nature. Old Mine Kashmir Sapphires, with their vivid cornflower-blue hue and velvet-like feel, are a prime example. Discovered in the late 1870s, these extremely rare stones were mined for only half a century. By the late 1920s, the supply had been exhausted, and official production ceased.
Today, blue sapphires are mined in locations as diverse as Sri Lanka, Montana, and Australia, yet none match the unique character and quality of those from Kashmir. Limited in number, these old-mine gems remain the finest and rarest sapphires in the world and command deservedly high prices. Conversely, truly stunning Siberian amethysts, while also incredibly hard to find, remain disproportionately affordable.
The key takeaway? The term ‘rare’ should be used only to describe a gem of exceptional quality and scarcity, regardless of its price.
HOW ARE DIAMONDS VALUED?
THE 4CS OF CARAT, CUT, COLOUR, AND CLARITY ARE ESSENTIAL CRITERIA FOR GRADING A DIAMOND. HOWEVER, THEY DON’T TELL THE WHOLE STORY. TWO DIAMONDS WITH THE SAME GRADES CAN LOOK VERY DIFFERENT, AND COMMAND VERY DIFFERENT PRICES.
EXCEPTIONAL WHITE ASSCHER CUT DIAMOND
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HARRY WINSTON PEAR SHAPE DIAMOND RING, 13.9 CARATS
EnquireAn important jewel, this exceptional Harry Winston Diamond and Platinum ring features a 13.9 carat, exceptional white, internally flawless (type IIa), historic cut, pear shape diamond, accented by two tapering baguette cut diamonds. From the original date of purchase, we know that Harry Winston, himself, handpicked the diamond.
The Lesotho Promise 75 Carats
GET EXPERT ADVICE ON BUYING AND SELLING RARE GEMSTONES
We offer a bespoke service across the UK, Europe, North America, the Far East and beyond. In-person or online appointments are available at your convenience and at your preferred location. Whether you are buying for beauty or long-term investment, or considering selling a gemstone from your collection, we are here to help.
Our services include:
- advice on gem quality and rarity
- gemstone certification
- sale and purchase strategy
- global sourcing
ASSESSMENT, PROVENANCE AND REGULATION
Assessment:
A gemstone cannot be properly assessed at a glance. True assessment requires the skills of an experienced graduate gemmologist, as beauty can be as persuasive as it is misleading. We examine the factors that drive quality and desirability, including cut, colour, clarity, treatment, and origin. We also consider how a stone presents in the real world, not merely on paper. To help you make informed decisions, we offer complimentary valuations for precious stones, including diamonds, rubies, emeralds, and sapphires, and arrange their certification.
Provenance:
Provenance is documented proof of a stone’s ‘backstory’. It can include evidence of origin, purchase and ownership history, together with supporting gemmological certification from a recognised laboratory.
Providing a complete supporting paper trail for older stones can be difficult. Stones with historic or royal associations are a different matter and are more likely to retain formal records.
Regulation and certification:
Janus Jewels is fully compliant with the jewellery trade’s main regulating bodies. All diamonds are accompanied by Gemological Institute of America (GIA) reports.
All rough diamonds are compliant with the Kimberley Process Certification Scheme. All coloured stones are certified by the Swiss Gemmological Institute (SSEF) and/or the Gemmological Certification Services laboratory (GCS).
Janus Jewels is fully compliant with the jewellery trade’s main regulating bodies — see here for more details.
