The “Cutting” Minute

Since the dawn of time, Mankind has polished and cut gemstones to adorn its jewellery.

Tutankhamun’s burial mask testifies to it, with its calibrated Lapis-Lazuli, Turquoise and Carnelian, in rectangular and trapezoid shapes. The Lapidary equipment was then very rudimentary.


It was probably consisting of a wooden disc covered with a dried buffalo hide coated with abrasive powder. Over centuries, this reel formerly operated by foot evolved into a more sophisticated workbench, very accurately described by Chriten. Diderot mentioned his drawing in the Encyclopedia he published 1751.

Jam-peg and dop, Maison Piat

The Lapidaries from the Jura region improved the frame of this workbench that supported the dop on which the gem was attached, to create the étui mécanique (a metal piece holding the dop) and the jam-peg (a rigid metal plate in which the specific “mechanical dop holder” is inserted). This equipment, far more precise, is still used nowadays.


At that time in Jura, tradition wanted each gemcutter’s son to receive a wooden disc at birth. This material was very hard and was immersed in oil until the child reached 18 years old, to become a wood grinder tough enough to polish cabochons.


Depending on use – cutting or polishing – the grinder can be made of copper, pewter or even felt. Nowadays, some countries such as Sri Lanka still use a foot-operated reel but technology an increasingly important place in the workshops