That is a simple question without a simple answer. Historically, colored gemstone cutting and carving go back at least 5000 years, but the techniques used to cut diamonds have only been used for several hundred. Diamonds are the hardest material known to man and only diamond can be used to cut another diamond.
Diamond has different degrees of hardness depending on its ‘grain’, which makes knowing how to cut diamonds a tedious business. And diamonds, by comparison, take a great deal more time to cut and polish then corresponding colored gemstones. Other than that the tools and techniques used have a lot of similarities.
A colored gemstone cutter has a specialized knowledge of the stones that are cut, as diamond cutters have with diamonds. Colored gemstones may require a specialized polishing technique, whereas diamond always uses the same.
Colored gemstone cutters will have to vary the cutting angles according to the stone to gain the best brilliance, diamond cutting angles are well established and usually only vary to maximize recovery of the rough. There are other differences as well, but they get so technical that this is where I usually see peoples eyes glazing over – so let’s stop here. We can find the most beautiful gemstones in Australia’s Central Queensland Sapphire Gemfields.
What is the difference between colored gemstones clarity and diamond clarity?
There are a number of rules governing the clarity of diamonds and colored gemstones. The one most highly regarded and widely recognized is that developed by the Gemological Institute of America or GIA.
While there are similarities to the diamond clarity grading, that similarity is only in the use of some similar-sounding terms. Diamonds are singular in type – they are all the same in general crystal habit and class, but colored gemstones occur in all sorts of crystal classes and habits, and have characteristics unique to themselves.
For instance, it is quite normal for Emeralds to have veils and other inclusions, commonly called garden or Jardin. With this in mind, the characteristics of each variety of gemstone can be grouped with others of like habits. These are classed into three groups Called Type 1, Type 2, and Type 3 – then the general definitions of Internally Flawless (IF), Very Very Slight inclusions (VVS), Very Slight inclusions (VS), Slight Inclusions (SI), and Included (I).
The type that they fall in and the size and appearance of inclusions determine how they are classed. The Emerald then isn’t compared with the topaz as they have different crystal habits, so a Type 3 Emerald with a VVS rating, will have more apparent inclusions than the Swiss Blue Topaz, a Type 1, with a VVS rating. To learn more about Gemstone cutting practices, read this article.
Every year in August, there’s a great Gemfields festival (Gemfest) held in Anakie, in Central Queensland, Australia. If you have the chance to get there, don’t waste it!