The Prodiam diamond upgrade promise
The diamond upgrade promise: a purchase is the start of a relationship, not a transaction.
The Prodiam diamond upgrade promise is a lifetime trade-up framework: most jewellers price a diamond as if it has to last a lifetime in one ring, we treat it as if it has to last a lifetime through several. This is the framework that makes that real.
The promise, in three sentences
- Every Prodiam stone can be traded back to us. At any time, against any future commission of greater value, with the conversion benchmarked transparently to the Rapaport list on the day.
- The valuation happens in your presence, against a public reference. No opaque margin. We show you the per-carat discount the trade is currently paying for the grade, and that is the trade-in number.
- The setting is valued separately on its gold content. 18 kt and platinum carry meaningful metal value; we pay it into your credit alongside the stone valuation.
How the conversion works in practice
There are three routes, and we give you the firm figure in writing before anything is decided.
| Trade-in path | How the credit works |
|---|---|
| Stone returned to Prodiam, traded against an upgrade commission of greater value | The Upgrade Promise core: the strongest credit, because it is our own stone going back into a larger one. |
| Stone returned and re-set into a different ring (heirloom redesign) | You keep the stone; we charge only the design and bench. The credit conversation does not apply. |
| Stone bought back outright, no upgrade commission | The buy-back route, structurally different and priced for cash, not for relationship. |
The first row is where the relationship pays: trading an original Prodiam stone up into a larger one returns the most value, because we know exactly what we sold you and it goes straight back to the bench. The exact figure is always benchmarked to the Rapaport list on the day and quoted firm, in writing.
What we trade, what we do not
| What | How we treat it |
|---|---|
| Prodiam-original GIA-graded stones (with our hand-over cert) | Highest conversion. Same-day valuation against Rapaport. |
| GIA- or EGL-graded natural stones from elsewhere | Re-graded if needed, then valued against the Rapaport list on the day at a trade discount. |
| Signed branded pieces (Tiffany, Cartier, Graff, Harry Winston, Van Cleef) | Case-by-case. Brand premium plus stone valuation; condition-sensitive. |
| Estate and inherited diamond jewellery | Stones graded if not currently certified; setting valued on its gold content. |
| Older European, transitional or Old Mine cuts | We may recommend re-cutting to GIA Excellent for materially better re-supply value; we explain the weight loss honestly. |
| SADPMR-licensed SA rough | Bought against the next DBSSSA viewing benchmark. |
| Will not trade | Why |
|---|---|
| Lab-grown / synthetic diamonds | We are a natural-only house. See the comparison guide. |
| Moissanite, cubic zirconia, white sapphire | Not diamonds. |
| Stones with no laboratory grading and no clear provenance | We cannot value blind. |
| Stones from outside the Kimberley Process system | Compliance floor. |
What this looks like over twenty years
The Upgrade Promise is designed for a multi-decade relationship, not a one-off transaction. The pattern we see most:
- Year 0: Engagement-grade stone, often 0.70-1.20 ct, GIA-Excellent.
- Year 5-10: Tenth-anniversary upgrade. Original stone traded back at a strong credit toward a larger anniversary stone in the 1.50-2.00 ct band. Often re-set into the original ring or a new design.
- Year 15-20: Larger anniversary stone or a complementary right-hand piece. Heirloom intentions discussed.
- Year 25-50: Pieces remounted, redesigned, or passed down. The Heirloom Redesign service often comes back into play.
We have clients in their 70s today who bought their first Prodiam piece in the late 1990s and are now commissioning the third generation of their family’s diamonds with us. That is what the Promise looks like, played out over thirty years.
Frequently asked questions
What can I trade in?
Original Prodiam stones (with the GIA report we issued at hand-over) at the highest conversion. GIA- or EGL-graded natural stones bought elsewhere. Signed branded pieces (Tiffany, Cartier, Graff) on a case-by-case basis. Estate and inherited diamond jewellery. SADPMR-licensed SA rough. Lab-grown stones and simulants are excluded, we are a natural-only house.
How much credit do I get for my stone?
For an original Prodiam stone, the trade-in credit is a strong proportion of your original Prodiam invoice value, applied to a new commission of greater value, because you bought it from us and we know exactly what it is. For a GIA-graded natural stone we did not sell originally, the credit is benchmarked to the Rapaport list on the day against the stone's current grade.
Signed pieces are valued separately on brand and condition. We give you the firm figure in writing before you commit.
How is the valuation done?
In your presence, with the GIA report on the desk, against the current week's Rapaport price reference for the size-colour-clarity-cut combination. We show you the discount-from-Rap that the trade is currently paying for that grade, and that is the trade-in number. There is no opaque margin baked into the offer.
Is there a minimum trade-in?
For Prodiam-original stones, no minimum. For non-Prodiam stones, the working minimum is roughly 0.30 ct GIA-graded; below that, the grading and re-supply economics typically do not justify a trade-in transaction (we will buy the stone outright or refer you to a buy-back desk that handles smaller goods).
Do I have to upgrade to a Prodiam stone?
For trade-in (credit toward a new piece), yes, the credit is applied to a new Prodiam commission. For outright buy-back (cash for the stone, no commission), no, see the We Buy page. The two are distinct transactions; the trade-in conversion is structurally higher than the cash buy-back because we are committing to a future commission with you.
What about the setting and metal of the original ring?
The setting is valued separately on its gold content on the day. 18 kt and platinum carry meaningful metal value; lower-karat or hollow settings carry less. We pay that metal value into the trade-in credit alongside the stone valuation.
How long does a trade-in take?
For a Prodiam-original stone, typically same day, we have the original cert on file and the valuation is straightforward. For a non-Prodiam stone, 1-3 business days if we need to re-grade or independently verify. The new commission then proceeds on its own service timeline (Heirloom Redesign, Stone-You-Own, Bridal Set Design, or a stock piece from inventory).
What happens to the original stone after I trade it in?
For a Prodiam-original stone, it goes back into Prodiam Trading inventory or into the reservation register for another buyer. For a non-Prodiam stone we have re-graded and accepted, the same. Stones with cut grades materially below modern targets may be sent to the Procut DCW bench for a re-cut to GIA Excellent before re-supply; this is one of the few productive uses of older stones with weight to spare.
Read the worked story
For a step-by-step walk-through of an upgrade from a chain-store engagement ring to a GIA-Excellent shy-weight stone on the same budget, see From a mall-chain ring to a GIA Excellent-cut stone, on the same budget.