Black Natural Fancy Diamonds

Natural black diamonds are real diamonds — the same crystalline carbon as a colourless brilliant — coloured by dense graphite or hematite inclusions that scatter rather than reflect light. The effect is a deep, opaque black that reads as solid carbon rather than transparent stone. President Jewellers stocks loose natural black diamonds from 0.25ct to 5ct in round, oval, pear and cushion cuts, and mounts them in bespoke engagement and dress rings hand-finished in our Hatton Garden workshop.

Natural vs treated — what you are actually looking at

Black diamonds split into two categories. Carbonado is a polycrystalline natural diamond mined principally in Brazil and the Central African Republic — formed differently from clear diamonds, with billions of microscopic crystals fused together, giving it the highest toughness of any diamond. Treated black diamonds start as lower-grade colourless or brown diamonds and are colour-modified by high-temperature, low-pressure heat or by irradiation. Both are real diamonds; both register 10 on the Mohs scale. President Jewellers labels every stone honestly — every listing states whether the centre is carbonado, lab-grown, or treated.

Cuts that suit a black diamond

Because a black diamond does not return light through the table the way a transparent diamond does, the cut serves a different purpose — outline, surface polish, and proportions matter more than facet-by-facet brilliance. Round brilliants give a tight, symmetrical disc. Oval and pear cuts elongate the finger. Cushion and emerald cuts read as soft, faceted slates. Rose cuts have made a strong return in 2026 — domed crown, flat back, perfect for a black diamond because the polished surface catches light without trying to refract it.

Settings — five we make most often

Bezel. A continuous metal rim around the stone — protects the edge of a black diamond, which is more brittle at the girdle than a white diamond, and lets the black sit flush. Four-prong solitaire. Cleanest profile, lets the stone do all the work. Halo with white melee. A ring of colourless diamonds around the black centre maximises contrast. Three-stone. A black centre flanked by two colourless side stones reads as a statement piece. Pavé band with hidden halo. Streetwear-influenced setting where the band itself carries colour and the centre stone reads as a single dark gem floating above.

Pricing — what a black diamond actually costs in the UK

Natural black diamonds are priced well below colourless diamonds of comparable size — typically $250 to $800 per carat for treated stones, and $1,050 to $3,300 per carat for carbonado of jewellery grade. A 1.0ct treated round set in 18ct gold ring at President Jewellers starts at approximately $1,600; a 1.0ct carbonado in platinum with diamond-set shoulders sits closer to $3,700. Lab-grown black diamonds, where you want the look at the lowest budget, sit at $200 to $450 per carat. Every quote is itemised before commitment.

Hatton Garden bespoke — how a black diamond ring is made at President Jewellers

Every ring set with one of our black diamonds is bespoke. The process is the same as for our colourless diamond rings. You select a stone from our inventory or have us source one. We produce a CAD design for your approval. A silver or wax sample is made for you to try on. We cast in your chosen metal — platinum, 18ct white, yellow or rose gold, or 9ct gold — and finish, set, and polish. The ring is hallmarked at the London Assay Office and delivered with free insured UK delivery. Free lifetime resizing where the setting permits. Lead time 7 to 14 business days from sample approval.

Frequently asked questions

Are black diamonds more expensive?

No. Natural treated black diamonds and lab-grown black diamonds sit well below colourless diamonds of the same carat weight. Treated black diamonds price at $250-$800 per carat in the UK in 2026; lab-grown black diamonds at $200-$450 per carat. Carbonado — the rare polycrystalline natural black diamond — is the exception and prices at $1,050-$3,300 per carat depending on jewellery-grade quality. A colourless 1ct diamond at G/VS1 trades at $5,300-$8,600 by comparison.

Are black diamonds expensive in the UK?

Black diamonds are among the most affordable diamond options on the US market. A 1.0ct treated black diamond ring at President Jewellers starts at approximately $1,600 in 18ct gold. A 1.0ct natural carbonado stone in platinum sits at $3,700. A 1.0ct lab-grown black diamond starts at $950. Higher quality is generally about origin (carbonado vs treated) and the metal/setting around the stone, not the carat weight itself.

What does a black diamond ring signify?

Black diamonds are traditionally associated with strength, resilience, and unconventional love. The hardness and toughness of carbonado — the toughest diamond variety known — has lent the stone a meaning of unbreakable bonds. In contemporary engagement rings, a black diamond is often chosen for its distinctiveness without departing from the diamond tradition. The meaning is personal; the stone takes on whatever the wearer assigns to it.

Is a black diamond a real diamond?

Yes. Black diamonds are pure crystalline carbon, the same material as colourless diamonds, registering 10 on the Mohs hardness scale. The black colour comes from dense graphite or hematite inclusions (in natural and treated black diamonds) or from the lab growth process (in lab-grown black diamonds). Carbonado, the rare polycrystalline natural variety, is made of billions of fused microcrystals and is actually tougher than any single-crystal colourless diamond.

How much is a 1 carat black diamond ring worth?

A 1.0ct black diamond ring in the US ranges from $950 for a lab-grown stone in a silver setting, to $1,600 for a treated natural stone in 18ct gold, to $3,700 for a carbonado in platinum with diamond accents. The variation is driven primarily by the centre stone origin (lab-grown vs treated natural vs carbonado) and the metal of the ring. President Jewellers itemises every quote so you can see exactly where the price is going.

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