The cutting pipeline

  1. Sourcing. Most rough is acquired at scheduled DBCM viewings in Johannesburg (under EBC programme allocation). The balance comes from independent South African diggers and tender-house parcels in Kimberley, Wolmaransstad and Schweizer Reneke. Relationships built up over the founder’s 25-plus years in the SA trade. Every parcel is logged against its SADPMR-licensed acquisition record.
  2. Planning. Each rough stone is mapped on a Sarine or equivalent rough-planner to determine the maximum-yield finished outcome. Decisions to weight-retain versus quality-retain are made stone by stone. We do not run a default weight-yield policy that compromises cut grade.
  3. Sawing and bruting. Where the rough morphology calls for it, sawing is laser-cut; bruting is mechanical. Each intermediate-state record is photographed for the SADPMR audit trail.
  4. Polishing. Bench polishers cut to a GIA-Excellent target on every commercial-grade stone. Cushion, oval, pear, emerald, baguette and fancy shapes follow the equivalent Excellent-tier benchmarks for their geometry.
  5. Grading and certification. Finished stones are sent for GIA or EGL grading depending on the buyer’s target market. The certificate is the pass-off document. We do not retail an uncertified stone above the commercial cutoff.
  6. Disposition. Certificated stones either move into the Prodiam retail inventory (where they appear on prodiam.co.za) or are placed with trade buyers under the EBC outflow channel. Both routes are logged against the original rough acquisition record so the SA-source provenance is never broken.

What we cut, and what we don’t

Cuts run in-house
Round Brilliant, Princess, Cushion, Oval, Pear, Emerald, Marquise, Asscher, Radiant, Heart, Baguette.
Cut grade target
GIA Excellent (equivalent to AGS Ideal). No commercial-grade stone is cut to less.
Carat range
Routinely 0.30 ct to 5.00 ct finished. Larger stones (5 ct +) handled on commission.
Colour range
D to N white series, plus Fancy Yellow / Fancy Brown in select rough.
Clarity range
FL to SI2 routinely. I-clarity polished only on commission.
What we do NOT cut
Lab-grown / synthetic diamonds. CVD/HPHT-treated stones. Coloured stones (sapphires, rubies, emeralds. Refer to specialist cutters).
Bench tour
By trade-only appointment. Trade contact →

Quality control standards

Every finished stone passes a three-step QC:

  1. Bench QC. The polisher signs the stone off against the planner’s target geometry.
  2. Master QC. A second polisher independently checks symmetry, polish, and proportions before the stone leaves the bench.
  3. Lab grading. The independent GIA or EGL certificate is the externalisation of QC. Cut, colour, clarity, polish, symmetry, and fluorescence are graded by a third party with no commercial interest in the stone.

A stone that fails any of the three is recut or downgraded. The SADPMR record gets updated; nothing is destroyed.


The bench portfolio

Past pieces, stones we have cut and polished and that have since sold, are catalogued in the Past Pieces gallery at the retail sister brand. That gallery is the public proof point for the cutting pipeline described on this page.

View past pieces at Prodiam →