How these collections are built

Every piece on this page starts at the cutting wheel. The centre stone is selected, polished to GIA Excellent or AGS Ideal cut grade at Procut Diamond Cutting Works, and then handed to the bench. A piece is designed around that specific stone. CAD, wax, casting, setting, polish, all in Bedfordview. We do not outsource manufacturing.

Calibrated sides for three-stone rings and eternity bands are cut from the same parcel where possible, so colour and clarity match within one grade across the piece. The Rapaport-discount wholesale pricing structure that applies to a loose Prodiam stone applies to the centre stone of any commission. The manufacturing labour is priced separately and quoted on the sketch.

Each collection below is a starting point, not a fixed catalogue. The brief at the start of the commission is what determines the final piece. Most pieces below have been made before in some form; bring a reference, an inherited stone, or a starting carat weight, and the bench will quote.

One stone, ideal cut, classical setting

The Solitaire Collection

Round brilliant and oval ideal-cut centre stones in classical six-claw, four-claw and basket settings. The stone we cut is the entire piece. The metal is there to hold it.

For whom: First engagement rings; replacement stones for a beloved heirloom setting; the buyer who has read enough to know that an Ideal cut grade does the work of an extra colour grade.
Lead stones: 0.50, 0.70, 1.00, 1.50, 2.00 ct, GIA F to H, VS to SI1, Excellent cut grade.
Related: /services/bridal-set-design/ · /custom-engagement/ · /loose-diamonds/

Past, present, future. Centre plus calibrated sides.

The Three-Stone Collection

Three-stone rings in classical and contemporary geometry. Centres from 0.70 to 3.00 carats with calibrated sides matched on the bench, never bought as a kit. Common pairings: round centre with round sides, oval centre with pear sides, emerald centre with trapezoid sides.

For whom: Anniversaries, vow renewals, the buyer who wants narrative meaning in the geometry of the ring.
Lead stones: Centres 0.70 to 3.00 ct, GIA D to H, sides cut at Procut DCW to match within one colour and one clarity grade of the centre.
Related: /services/bridal-set-design/ · /services/heirloom-redesign/ · /stories/heirloom-three-stone/

Calibrated rounds, princesses, emeralds. Channel, shared-claw, U-set.

The Eternity Collection

Full and half eternity bands. Stones calibrated and matched on the bench. Cut grade enforced on every stone, not just the centres. Channel set, shared-claw and U-set construction available; we do not make pressure-set bands.

For whom: Anniversaries, push presents, the second band that meets the engagement ring at the knuckle.
Lead stones: Round, princess, emerald, baguette. 0.05 to 0.25 ct each, total weights 1.00 to 5.00 ct. Colour matched to within one grade across the band.
Related: /projewel/ · /custom-engagement/ · /services/bridal-set-design/

Upgrades, milestone pieces, the second ring.

The Anniversary Collection

Built for the buyer who already owns a Prodiam stone and wants the next chapter. The Upgrade Promise honours a meaningful percentage of the original Prodiam invoice (typically seventy to ninety percent, benchmarked to Rapaport on the day) toward a larger or rarer centre stone. See the Upgrade Promise for the full framework.

For whom: Tenth, fifteenth, twenty-fifth anniversary buyers stepping up the centre stone, adding a halo, or commissioning a second piece to wear with the original.
Lead stones: Wide range. Most clients move from a 1.00 ct round to a 2.00 ct oval, or from a solitaire to a three-stone. We hold the previous stone in safekeeping while the new piece is being made.
Related: /upgrade-promise/ · /services/heirloom-redesign/ · /stories/upgrade-from-mall-chain/

Heirloom redesign. Inherited stones, reset for the next generation.

The Heritage Collection

The piece you commission when an inherited stone needs to come out of a setting that is no longer worn. We unset, repolish if the cut grade calls for it, and remount in a contemporary or period-faithful design. The original metal is melted, refined and either kept aside or used in the new piece, your choice.

For whom: The grandchild stepping into a great-grandmother's diamond. The widow remaking a wedding band into a pendant. The buyer who inherited a brooch and wants two earrings.
Lead stones: Anything you bring in. Recutting and repolishing handled at Procut DCW; metal work at the in-house bench.
Related: /services/heirloom-redesign/ · /services/stone-you-own-customs/ · /stories/heirloom-three-stone/

Engagement ring, wedding band, eternity. Designed as one piece.

The Bridal Set Collection

A complete set designed at the same time, manufactured at the same bench, in the same metal lot. Engagement ring, wedding band that meets it at the shoulder without a gap, optional eternity band for an anniversary. Many buyers commission the engagement ring first and the set later; the original CAD file is kept on record so the bands match.

For whom: The buyer who wants the rings to read as one piece, not three accidents.
Lead stones: Engagement centre 0.70 to 3.00 ct. Wedding band optionally set with calibrated stones. Eternity band typically commissioned at the first or fifth anniversary.
Related: /services/bridal-set-design/ · /custom-engagement/ · /projewel/

Brief us on a piece

Send a sketch, a reference photo, or a target carat weight to darren@prodiam.co.za, or use the contact form. The bench quotes within one working day on most commissions. The deposit on commissions is fifty percent, balance on completion. Lead times run six to ten weeks depending on complexity.