Sell your diamonds

How selling a diamond works

1. Tell us about it. Use the form below to describe the piece: type, shape, approximate carat, colour and clarity if you know them, certificate details, metal, and whether you still have the box or receipt. Add photos and a copy of the certificate if you have one.

2. Receive an indicative offer. A specialist reviews your details privately. You will receive either a no-obligation indicative offer or a request for a specific extra photo or document.

3. Secure handover. If you are happy to proceed, we explain the insured send-in or a suitable in-person check. The exact option depends on the item, its value and your location, and is agreed before anything leaves you.

4. Inspection and payment. We confirm the diamond and any setting match what was described. If something material differs, we explain it before finalising. Payment is made by the agreed method once checks are complete, and the timing is confirmed with your handover instructions.

How we value a diamond: the 4Cs and beyond

Carat is weight, not size: one carat is 0.2 grams. Value does not rise in a straight line with weight, so two half-carat stones are not equivalent to one stone of one carat.

Colour is graded on a scale that begins at D (colourless) and moves through to Z. Small differences in grade can be hard to see by eye but are significant to a buyer.

Clarity describes inclusions and surface features, from Flawless and Internally Flawless through VVS, VS and SI grades to I (included). Where an inclusion sits, and whether it is visible, matters as well as the grade itself.

Cut describes how well a stone is proportioned and finished, and is graded formally for round brilliants. Polish, symmetry and fluorescence are recorded on most reports and also influence demand.

Beyond the 4Cs we consider shape (round, oval, princess, cushion, emerald, pear, marquise and others), whether the stone is natural or laboratory-grown, any treatments, the metal and condition of any setting, and whether a piece is signed by a recognised house.

Certificates: GIA, IGI, HRD and no certificate

A grading report from a recognised laboratory such as GIA, IGI or HRD Antwerp gives an independent record of the stone: carat weight, colour, clarity, measurements and often a plotted diagram of inclusions. Many reports correspond to a microscopic laser inscription on the girdle, which we check against the report number during inspection.

If you have a report, enter its number in the form and upload a photo or PDF of it. Please keep the original safe. If you do not have a report, that is not a barrier to selling: the stone is assessed and tested in hand, and anything you know (a retailer's description, an old insurance schedule) is still helpful.

Insured postage and handover

Where an insured send-in is the right route, we explain the process, packaging and cover before you post anything. For higher-value pieces we may suggest an in-person check instead. Please do not send any item until we have agreed the handover with you.

What to photograph

For loose stones: the stone face-up on a plain white surface in daylight, plus the parcel paper or box it came in. For rings and earrings: the piece from above and each side, the inside of the band or the backs (where hallmarks and maker's marks usually sit), and any box, receipt or house certificate. Clear photos speed up your first response.