Diamond Polishing Robot: From the Scaif to ABB Arms

A diamond polishing robot does a job people have done at a spinning wheel since the 15th century: hold a stone at an exact angle and grind one facet after another until it matches a plan. Machines already took over much of the planning and cutting with scanners and lasers, and Antwerp has tested a machine that polishes on its own. This post follows the trade from the first polishing wheels to Antwerp and Surat, looks at this autumn's pressure on India's lab-grown diamond polishers, and asks where ABB robots could fit.

A polisher in Amsterdam checks a stone held in its tang above the polishing wheel, 2012. Photo: Ввласенко / Wikimedia Commons (CC BY-SA 3.0)

From Bruges wheels to Antwerp and Surat

The first guild of diamond cutters and polishers was formed in Nuremberg in 1375, and the point cut appeared in the second half of the 14th century. Tradition credits Lodewyk van Bercken, a 15th century jeweller born in Bruges, with inventing the scaif, a polishing wheel infused with olive oil and diamond dust that let polishers cut facets symmetrically. His biography is thin, but a bronze statue of him stands at the start of the Meir in Antwerp, a city that has been a focus of the diamond trade since the 15th century.

The Lodewijk van Bercken monument by Frans Joris on a facade at Jezusstraat and Leysstraat in Antwerp. Photo: Vasyatka1 / Wikimedia Commons (CC BY-SA 4.0)

Antwerp built its own polishing industry in the 1890s, when families from Amsterdam set one up there. From the 1960s much of that work moved to India, where labour was cheaper, and today it is concentrated in Surat. Speaking in Mumbai on 13 September, India's Union Home Minister Amit Shah said nine out of ten diamonds in the world are cut in the city and that more than 90 percent of the world's cut and polished diamonds are processed in India. Antwerp kept the trading, and Wikipedia puts the share of the world's rough diamonds passing through its diamond district at about 84 percent.

Polishers at their wheels in a diamond polishing works, photographed by the Dutch agency Anefo in November 1945. Photo: Theo van Haren Noman / Anefo, Nationaal Archief via Wikimedia Commons (CC0)

A stone is still planned, cleaved or sawn, bruted round and then polished by pressing it against a spinning disk with abrasive, before a final inspection. Planning was the first step to go digital. Scanners build a 3D model of the rough, and Sarine, which has worked on diamond technology since 1988 from Hod Hasharon in Israel, sells inclusion scanning and planning systems that find the flaws inside a stone before anyone cuts. Sawing can now be done by laser as well as by blade. Polishing stayed a hand job, and one stone can take a polisher all day.

A diamond worker at his machine in Netanya, Israel, in 1964, with racks of dops on the bench. Photo: Willem van de Poll, Nationaal Archief via Wikimedia Commons (CC0)

Fenix, lasers and pressure in Surat

Antwerp tried to answer high wages with a machine. In 2018 the Scientific and Technological Research Center for Diamonds (WTOCD), the research arm of the Antwerp World Diamond Centre, announced Fenix, which fully automates polishing after more than a decade of development. The AWDC said it polishes 10 to 20 times faster than a person, so a stone that takes a polisher all day is done in about an hour and a half, following the map made when the stone was planned. It makes one polished diamond per rough stone. "Today's wages simply make it too expensive to conduct this labor-intensive job in our country," said AWDC chief executive Ari Epstein.

Polishing by hand at the scaif: a polisher at a Tel Aviv diamond works in 1939. Photo: Matson Collection, Library of Congress via Wikimedia Commons (public domain)

Lasers are taking over parts of polishing too. In 2019 Synova, a Swiss laser company partly owned by De Beers, introduced DaVinci, an automated system that cuts and shapes round diamonds with a laser guided inside a water jet, which cools the stone and lowers the risk of cracking. Synova said steps such as crown and pavilion blocking, girdle bruting and repeated quality checks become redundant, leaving polishing as a final finishing step. The case for automation got stronger in Surat this year. Diamond World reported in September that price erosion has cut profits at lab-grown polishing units and squeezed wages, and that a shortage of skilled labour has become another concern.

Colourless lab-grown diamonds made by Syntechno, cut and polished, 2019. Photo: Igor Stratichuk / Wikimedia Commons (CC BY-SA 4.0)

We found no ABB robot in a diamond polishing line, so what follows is a possibility. In April ABB launched its first fully automated sanding and polishing cell, the OmniVance Collaborative Surface Finishing Cell, a self-contained plug-and-play unit built around a GoFa cobot. ABB says lead-through path recording and Wizard Easy Programming blocks cut programming time by up to 90 percent, so operators need no robotics expertise. ABB's separate force control software for grinding and polishing holds a constant pressure between tool and workpiece. Diamonds would need far finer tooling than the parts ABB shows. For moving stones between scanners, lasers and polishing heads, the dual-arm YuMi carries 500 g and offers grippers with built-in cameras.

A GoFa cobot sanding a curved panel inside ABB's OmniVance Collaborative Surface Finishing Cell, launched in April 2026. Photo: ABB

Where diamond polishing robots go next

In factories, lab-grown diamonds add to the case for automation. Shah told the industry that the lab-grown market could grow to nearly 50 times the size of the current diamond market in volume, and urged that everything from making the machinery to building brands stay in Indian hands. More stones means more handling between machines that already exist: scanners that plan, lasers that saw and shape, and polishing heads like Fenix that follow the plan. A small arm loading and unloading those machines is the most likely first job for a robot, with the polishing itself left to dedicated machines.

The OmniVance Collaborative Surface Finishing Cell, a self-contained unit with a GoFa cobot and a FlexPendant on its front. Photo: ABB

The harder question is jobs. Antwerp lost most of its polishing work to India on wages, and Surat now worries about both wages and skilled labour. ABB markets its single-arm YuMi as a way for small and medium firms to offset shortages of skilled workers, with lead-through programming that lets staff teach motions by hand. Botswana shows how fragile new cutting centres can be. HB Antwerp, which opened a diamond factory there, is scaling it back because rough supply promised by the state-owned Okavango Diamond Company under a 2023 agreement never arrived, managing partner Boaz Lev told Reuters in September. HB said it had invested more than $10 million in technology and infrastructure in Botswana, and that the machinery will stay for the employees who remain.

An engineer programs a single-arm ABB YuMi at a work table. Photo: ABB

New machines are a hard sell to small polishing units already squeezed on margin, and robots add integration costs on top. A cobot such as YuMi is designed to work beside people without fences, but the lasers and wheels it would serve still need their own guarding. The skills needed also move from the wheel to the screen, toward planning software, scanners and robot programs that are usually built and tested in simulation first, for example in RobotStudio. Our post on jewelry manufacturing covers what happens to the stones next.

A robotics class with ABB GoFa education cells and RobotStudio on screen. Photo: ABB

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