Specializations within ‘the Trade’

Cleavers treated the rough diamond first, giving the stone an even (crystal) shape and removing impurities from the rough stone. A cleaver would start by using another diamond (diamond is very hard and can be processed only by using another diamond) to make a notch in the rough stone and then split it with a cleavers’ knife and a cleavers’ hammer.

Because cleavers could indeed make or break the rough diamond, they received extensive training, were well paid, and had the highest status within the trade. Louis Gans was such a cleaver.

In the twentieth century cleaving was increasingly replaced by sawing, which was done with a rapidly rotating bronze wheel on which diamond powder (boart) was applied.

The next step was cutting, where the diamond acquired its basic shape. Cutting might be done manually by rubbing two diamonds affixed to sticks with cement against each other.

Like cleaving, cutting took place at home or in a small workshop into the twentieth century. Henri Polak, later president of the Algemene Nederlandse Diamantbewerkersbond [General Diamond Workers’ Union of the Netherlands] (ANDB), was trained as a cutter, as were the sisters Betje en Sophie Lazarus.

Over the course of the twentieth century, cutting was increasingly done with a machine.

Polishing was the last step. It was done on a rapidly rotating grinding wheel on which diamond powder was applied. The diamond was positioned in a holder (the cap) and pressed against the grinding wheel to polish each facet individually. A setter positioned and set the diamond in the cap, so that the polisher always faced the section of the diamond to be polished to a facet. In the twentieth century the mechanical cap was introduced, which had a clamp system enabling diamond polishers to place the diamond, rendering setters redundant. While polishing started out as a cottage industry as well, from 1820 this work increasingly took place at large workshops and factories. Jan van Zutphen, later the secretary of the ANDB, started his career as a polisher.

The ultimate form in which a diamond was cut and polished determined the level of difficulty and consequently also the wages cutters and polishers were paid.

The best-known form was the brilliant, in which the top (the table) and bottom were faceted to ensure optimal light reflection and thereby dazzle. This double processing made the brilliant more complicated than to polish and cut than the rose, and brilliant cutters and polishers were therefore paid more than rose cutters and polishers.