Introduction to Cabochon Cutting
Although tumbling is an easy way of polishing a lot of stones fairly cheaply, it is restricted in that only baroque (free form) stones can be produced from rough rock or pebbles.
As a hobby, tumble polishing is limited because it is not time consuming and for this reason people look to the next stage of gemstone cutting , called 'cabochon cutting.
A 'Cabochon is any stone which has been cut to a particular shape, usually oval, using a saw and grinding unit.
Machines enabling all the operations to be undertaken on one small unit are called 'combination machines.
These machines may also be used for cutting shapes (called preforms) out of stones which are to be tumbled.
The photograph alongside shows a Victorian mahogany, bench-type, hand operated, lapidary machine (suitable for Cabbing or Faceting), that was discovered in Calke Abbey, Derbyshire, after the National Trust took over it's administration. A similar unit is featured in a book on Agates published by the Natural History Museum