Cutting any gemstone is a specialized skill, and one that it takes years to perfect.
If you want to teach yourself how to cut opal, you will of course work with the least expensive varieties of opal rough, before you move on to the good stuff.
How do the professionals do it?
Opal miners sell their rough opal as parcels. Potential buyers sort through these, and it is their skill to decide how many precious opals can be cut from each piece.
There is never any guarantee as to what the eventual outcome will be, of course, which makes the life of an opal buyer an exciting and tense one.
The opal cutter uses a diamond saw to cut the rough opal into ‘rubs’ (opal in the rough shape of a stone). During this process, excess material such as “cracks” and “potch” (colourless opal) is removed.
The opal cutter must ensure that he (or she) keep the stone as large as possible, whch at times can be dfficult and calls for great skill, since each act of cutting reduces the size of the stone, obviously.
Because opal can burn or even crack if subjected to extreme temperatures, water must always be used when cutting, to avoid overheating due to friction.
When an opal is burned, that means its surface becomes pitted – no more smooth surface or polish.
