Bespoke diamond jewellery
Create a timeless piece
High quality designs

Devotion, affection & precision goes into every handcrafted piece of jewellery that leaves our workshop in Hatton Garden.

Devotion, affection & precision goes into every handcrafted piece of jewellery that leaves our workshop in Hatton Garden.

Solitaire Engagement Ring

The most classic, simple engagement ring is the solitaire engagement ring, which features a single round brilliant diamond lofted above a delicate precious metal band. 

Halo Engagement Ring

Halo engagement rings have been popular since the 1920s when glamour was the fashion rule. 

Diamond Wedding Band

View our stunning collection of women’s wedding bands from vintage-inspired styles to unique modern designs.

Diamond Eternity Bands

A modern take on the eternity ring, this set of rings is a perfect combination of uniqueness and style. Each of the rings are channel set with round brilliant cut diamonds.

GIA Certified

We select our diamonds using a universal standard certified by the G.I.A (Gemological Institute of America). This ensures that One Carat Diamonds sets its creations with the highest-quality diamonds, by being extremely selective through the G.I.A criteria known as the 4C’s; Cut, Colour, Clarity & Carat Weight.

Every diamond of more than 0.30 carats comes with a G.I.A certificate and individual certificate number engraved on the stone.

Check out our recent work

Take a peek inside our Wonderworld

See what our customers are saying about us

GIA Certified Diamonds
Hand made in UK
Exceptional Value
Customer Satisfaction Guaranteed
Hatton Garden London

Amazing engagement rings

Take a peek at these amazing designs

Want to see more designs for inspiration? Check out our portfolio gallery for more ideas

Diamond basic attributes – the 4Cs

4C represents Color, Clarity, Cutting and Carat. The 4Cs are the shared common attributes used by different grading institutes, to determine the quality and value of each diamond. Therefore, it is crucial to know the 4Cs before buying a diamond.

Learn About the 4Cs of Diamonds


Which refers to a diamond’s lack of colour. The less colour, the higher the grade.


Often the least important of the 4C’s because the tiny imperfections are often microscopic.


Is the most important because it has the greatest influence on a diamond’s sparkle.


Actually refers to the diamond’s total weight and not its size.

Gemstone Engagement Rings

Show your true colours with a custom non-diamond engagement ring designed just for you.