Amsterdam diamond city

Amsterdam was the diamond city of the world from the 17th century on. Virtually all cut diamonds were produced in Amsterdam. Jewish traders had introduced the processing of diamonds in Amsterdam around 1600. Jews could work in the diamond sector without limitations, as no guild existed for the profession.


Boas diamond cutters on the Nieuwe Uilenburgerstraat 173. Photo: City Archive Amsterdam.

The Boas Bros

The diamond profession expanded considerably shortly after 1870 as a result of a major diamond find in South Africa. The Boas brothers profited from this as well. Their father was a shoemaker, but the brothers Israël, Markus and Hartog mastered the diamond cutting profession and built the largest factory of that time on Uilenburg, with 357 grinders, 122 adjusters and 142 pupils.


Ceremony in the courtyard of Gebroeders diamond cutters. Photo: City Archive Amsterdam.

Optimal daylight

A large number of windows is characteristic of a diamond-cutting factory. It was necessary to make the most of the available daylight in order to adequately examine the small stones. The cutters sat side by side in the factory, at long workbenches with the grinders on top. These grinders were powered by steam energy. The boiler house and the chimney can still be found on the square in front of the factory.


GASSAN Diamonds now occupies the Boas building on the Uilenburgerstraat. Photo: Pauline Prior.

GASSAN Diamonds

Many diamond factories faced difficulties during the economic crisis of 1930. The Boas-factory switched to other activities. It accommodated a textile trading company, a stocking factory and a paint factory. The building was sold to GASSAN Diamonds in 1989, which meant the return of the diamond factory to Uilenburg (island). The grinding company is open for visitors. There is an exhibition on the diamond profession and diamonds are still cut here.