Step into the world of Exquisite Gemstones
Blacklock’s Rare Stones offering is a considered selection of the world’s most exceptional natural gemstones, with the historic expertise and meticulous service to match it. True distinction comes from access, not accumulation.
Leveraging a trusted international network, we source rare gemstones, scarce fancy coloured diamonds, and remarkable stones of genuine consequence. From vivid pink spinel or red spinel to Fancy Coloured Diamonds of exceptional colour saturation and intensity, each stone enters our world through relationships built carefully over generations. These are precious gemstones and diamonds for clients, collectors, connoisseurs, and those seeking the finest gemstones or a piece unlike any other.*
* Please note; We do not offer investment advice, nor do we suggest gemstones should be purchased as investments. Our clients are encouraged to choose stones for their inherent beauty, rarity, and personal meaning. As with all natural assets, their value is linked to quality, demand, and prevailing market conditions, and may fluctuate over time.
Rare Stones
The Rarest Expression of Sapphire Colour
Legacy
A Legacy of Sourcing the Exceptional
The Blacklock name has long been associated with the ability to recognise rarity long before it becomes obvious. Since 1832, our family has not simply traded in fine jewellery but has sought out the extraordinary, often in places or moments others might miss entirely. This instinct has been passed down through generations.
Discover the defining moments that reflect Blacklock Jewellery’s enduring pursuit of exceptional gemstones, a discipline that has shaped our reputation as one of Britain’s finest independent jewellers and beyond.
Legacy
Antique Arab Dagger - An Eye Trained By Experience
In the 1980s, Kenneth Ellis Blacklock was presented with an antique Arab dagger, richly adorned with gemstones and intricate goldwork. While many regarded it simply as an intriguing artefact, Ellis immediately recognised its deeper significance, both as an object of exceptional craftsmanship and as an object of historic and gemmological importance.
The dagger was set with rubies, emeralds, and sapphires, many of which displayed characteristics suggesting considerable age. In historic gemstone pieces, age can often provide important clues to geographic origin. Prior to the development of modern global gemstone supply chains, stones were sourced through regional trade routes, meaning older gemstones frequently reflect specific historic mining locations and cutting traditions. Such provenance can significantly enhance rarity, cultural value, and collector interest.
Ellis recognised that the gemstones within the dagger were not simply decorative additions, but integral components of a historic object whose materials and craftsmanship reflected centuries of trade, artistry, and cultural exchange. The delicate goldwork further reinforced the piece’s authenticity and craftsmanship, demonstrating techniques that are rarely replicated with the same refinement in modern manufacture.
Legacy
Recognising the dagger’s importance, it was subsequently placed on public display, attracting both local and national attention. The exhibition allowed the piece to be appreciated as an exceptional example of historic jewellery craftsmanship and gemstone use within ceremonial objects. In keeping with Blacklock’s long-standing position as trusted independent retailers and traders of important jewellery and objets d’art, the dagger was later placed with a new custodian.
The experience demonstrated the ability to recognise exceptional value beyond conventional fine jewellery settings — understanding gemstones not only as individual materials, but as part of wider cultural and historical narratives. Such discernment requires both specialist gemstone knowledge and an appreciation of historic craftsmanship traditions.
This moment became emblematic of the Blacklock approach, the ability to recognise exceptional craftsmanship wherever it appears, to understand the cultural and historic narrative behind an object, and to identify gemstones not simply for their presence but for their significance and rarity.
Discernment
Recognising overlooked excellence
Heritage Understanding
Seeing the story within the dagger
Gemstone Connoisseurship
Judging stones beyond certification
Trusted Stewardship
Connecting rare objects with their next custodian
Legacy
Green Emerald Crystal - Gemmological Expertise
Years after establishing himself as both fine jeweller and gemmologist, Ralph Blacklock encountered what appeared at auction to be a modest ‘green crystal ring’. To most observers, it suggested little more than an attractive coloured green gemstone. Grounded in formal gemmological training and years of practical experience, Ralph discerned the unmistakable qualities of a fine Colombian emerald and secured it.
Colombian emeralds have long been regarded as the benchmark for emeralds, celebrated for their vivid, saturated green colour, often described as possessing exceptional depth and internal luminosity. Unlike many other emerald sources, the finest Colombian stones display a rare balance of richness of colour and transparency, qualities that are highly prized yet increasingly difficult to find in natural, untreated examples.
At the time of acquisition, the emerald had not yet revealed its full potential. Following master cutting and polishing, the stone emerged as a rare natural gemstone of remarkable clarity and vivid colour presence. The transformation highlighted one of the most important aspects of emerald appreciation: the ability to recognise quality not only in its finished state, but within the stone’s ‘rough’ form.
Legacy
Green Emerald Crystal - Gemmological Expertise
Emeralds are unique among precious gemstones in that natural internal characteristics, often referred to as jardin or garden, are accepted as part of their identity and authenticity. The challenge lies in determining whether these features enhance the stone’s character or compromise its beauty and structural integrity. In this instance, the balance between clarity, colour saturation, and natural character confirmed the emerald as an exceptional example of its type.
The stone was ultimately placed with a new owner, continuing its journey from overlooked object to celebrated rare gemstone. These moments reveal the power of gemmological knowledge and practical judgement — recognising exceptional stones ahead of broader appreciation.
This sits at the heart of the Blacklock philosophy — combining gemmological expertise with instinctive judgement, allowing exceptional gemstones to be recognised long before their true character is fully revealed.
Gemmological Mastery
Technical expertise enabling accurate identification beyond appearance
Experienced Judgement
Confidence built through decades of handling exceptional gemstones
Gemstone Connoisseurship
Recognising beauty and rarity before it fully reveals itself
Stewardship of Rarity
Guiding rare gemstones from discovery to their next custodian
Legacy
Padparadscha beauty - Modern Connoisseurship
In 2019, Chris Blacklock sourced a rare Padparadscha sapphire through trusted specialist stone dealers in Thailand. Long revered across the Far East, Padparadscha sapphires have historically been less widely recognised in the United Kingdom, largely due to the extraordinary nuance required to define their colour.
A true Padparadscha sits within an exceptionally narrow colour threshold — a delicate balance of pink and orange often likened to the lotus flower at sunrise. Too pink, and the stone becomes a pink sapphire; too orange, and it is classified as an orange sapphire. The rarity lies in achieving perfect harmony between the two.
The stone was accompanied by certification from GRS, one of the world’s foremost independent coloured gemstone laboratories. Recognising that not all laboratory reports carry equal authority, Chris carefully assessed the certification alongside the sapphire’s colour balance, clarity, and natural character before securing it.
Legacy
Upon its introduction into the UK market, the stone reflected the growing international appreciation for exceptional Padparadscha sapphires, ultimately realising significantly greater value than at acquisition. While Blacklock sources gemstones for their beauty and rarity rather than investment, this moment reflected the strength of trusted global relationships and the confidence to act when exceptional stones appear.
Today, while Padparadscha sapphires are becoming more widely appreciated, truly exceptional examples remain rare and reliant on specialist international sourcing networks, access that Blacklock is fortunate to maintain through long-standing relationships within the global gemstone trade.
This Blacklock approach here combined global sourcing relationships with specialist gemstone knowledge and disciplined colour judgement, allowing exceptionally rare gemstones to be recognised and secured before wider market awareness emerges.
Colour Discernment
Recognising the delicate colour thresholds that define the world’s rarest gemstones
Global Specialist Relationships
Access to exceptional stones through trusted international partners
Laboratory Intelligence
Understanding certification authority and interpreting reports beyond surface detail
Confident Timing
Acting decisively when truly exceptional gemstones become available
The Blacklock Eye
Generations of discernment. One enduring philosophy.
These moments are more than family stories; they define how Blacklock sees and sources exceptional gemstones. Across generations, we have maintained an instinct to recognise opportunity where others may not, and to identify rarity in its earliest and most unrefined form. Above all, they reflect the depth of knowledge and judgement we bring to every decision made on behalf of our clients.
This legacy guides every gemstone we select today, whether recognising the promise of a rare Mogok spinel in rough form or securing an exceptional Fancy Vivid Pink diamond from a tightly held parcel. Each stone is personally inspected and assessed by Chris Blacklock FGA, upholding standards refined by the Blacklock family since 1832.
How We Assess Rarity
A Disciplined Approach
Rarity is never about size alone. At Blacklock, every stone is evaluated through a multi-layered lens that balances beauty, scarcity, provenance, and long-term desirability. Our approach blends generational knowledge, internationally recognised grading standards, and modern gemmological precision, with every final judgement guided by the trained eye of Chris Blacklock FGA.
Principles of Rarity
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Colour
Beyond the D–Z diamond colour scale and the separate grading systems applied to fancy coloured diamonds, colour is judged through purity of hue, balanced tone, and depth of saturation, the enduring markers of exceptional coloured gemstones.
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Clarity
Inclusions are judged for beauty, position and authenticity. Diamonds follow recognised clarity grading standards, while coloured gemstones are assessed relative to the natural characteristics of each species.
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Cut
Proportion is critical to both brilliance and colour. While round brilliant diamonds adhere to recognised ‘ideal’ proportions that maximise light return, coloured gemstones require a more discerning evaluation: is there any windowing, or does the stone remain lively, with evenly distributed colour and depth?
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Carat
Carat measures weight, not presence. Its importance varies by stone; currently, fine unheated sapphires exceeding five carats are considered exceptionally rare and highly sought after.
1 carat = 0.20grams -
Rarity & Provenance
Each gemstone has natural scarcity thresholds. Gemstones from historic regions such as Kashmir, Burma, and Vietnam often command a premium due to their rarity and provenance. Together, these characteristics contribute to enduring collector desirability and long-term significance.
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Sourcing & Verification
Sourced through trusted global relationships and leading laboratories. Our preference is for gemstones certified by leading authorities: GIA for fancy coloured diamonds, and SSEF, Gübelin, and GRS for coloured stones.
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Beauty
Presence, harmony, and natural elegance remain our final authority. A trained eye is essential, as what appears exceptional at first often reveals its true quality only through experienced assessment and lasting aesthetic appeal.
Chris Blacklock is a qualified Gemmologist (FGA) and Professional Jeweller (PJ Dip). A Fellow of the Gemmological Association is recognised as the most prestigious gemmological qualification in the gem and jewellery trade.
What sets Blacklock apart
Independent Jeweller
The Advantage Of Independent Excellence
We buy with discipline and clarity. Operating without the structural overheads of global luxury houses, yet working directly with the same diamantaires, cutters and gemstone specialists, allows us to secure rare stones at considered prices — and to pass that advantage on to our clients.
Our long-standing, trusted relationships and price guarantees ensure exceptional quality, delivered with transparency and respect for value. This is a model grounded in integrity.
Individual Sourcing
For Clients Seeking Something Truly Individual
Many of our rare stones are not listed or detailed here. Some leave our hands within hours or days of arrival; others are quietly reserved for collectors, bespoke commissions, or heirloom designs.
For those in pursuit of a stone of extraordinary presence and rarity, we would be pleased to offer our guidance by discussing your requirements directly with Chris Blacklock.
At Blacklock, rare stones are selected with an emphasis on natural rarity, exceptional beauty, and long-term significance. We source rare gemstones, rare coloured gemstones, fancy coloured diamonds, and collector-grade stones through trusted partners established across generations.
Stone First
From Exceptional Stones to Enduring Design
A rare stone is revealed, not imposed upon. At Blacklock, exceptional gemstones are first understood, then given form through considered design and masterful craftsmanship.
The result is high jewellery that honours the natural character of each stone, transforming rarity into artistry. Considered careful sourcing forms part of the journey, but it is through design and craftsmanship that a gemstone finds its fullest expression — as a creation rich in story, significance and longevity.
The Blacklock Knowledge Library:
Rare Gemstones and Diamonds FAQs
Rarity is never determined by a single attribute. It is the convergence of colour, clarity, carat weight, origin, and the natural scarcity of the material itself. Some stones are rare because the mines that once produced them have long since fallen silent. Others are rare because nature only creates them in exceptionally small quantities. At Blacklock, we examine each stone through this full lens, understanding not just what it is, but why it matters.
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Discover the Exceptional. Get in touch today.
