Curious about diamond cutting

[ponyrider]

I am not even sure if I am allowed to ask this, but I am seriously curious about how diamonds are "cut". What does this actually mean? How are the inside facets cut, or do they just appear when the outside of the rough stone is cut? What makes someone able to do an excellent versus a good cut? Is it precision? Talent? Both? How does the process of doing an excellent cut compare to a good cut? Chemically, I understand how the color and inclusions (and obviously size) occur in diamonds, but I am just baffled by the whole idea of cutting stones.I would also love any links to articles or readings on this topic. If it helps, I am certainly not planning on taking p diamond cutting as a hobby, but rather, this is partly to quench my own interest and because I have students who are doing independent research projects (advance level 8th graders) and a few of them are interested in gems as a project. They (boys, if you can believe it) are gaga over the few cz stones I gave them to play with (showing them the fog test and the see-through test, as well as letting them play with my loupe and calipers (can you say "cz's flying all over my classroom - 8th grade boys can be a bit clumsy).
-=Vicki=

 

[VRBeauty]

Vicki:

I'm guessing that what you refer to as "inside facets" is actually an optical illusion - in most the facets that appear to be inside the stone are actually reflections of the facets you can see and feel on the outside of the diamond. If you look at the diagrams of diamonds in the "knowledge" section, you'll see all the facets used in a modern round brilliant diamond, and they make up the surface of the diamond. I said "in most cases" earlier because there are some very fancy laser cut techniques that might include facets or cuts in the interior of the stone - but you're not likely to see these stones outside of gem shows or high-end galleries.

As to how diamonds are cut, this thread shows the cutting progression for a fancy shape (octavia aascher) that was recently cut for a PS member: https://www.pricescope.com/forum/rockytalky/the-rough-for-my-octavia-pics-t203024-180.html

Daniel Stair, who cuts mostly colored gemstones, has also posted pictures showing the progression of cutting a stone is cut similar to a modern round brilliant: http://www.customgemstones.com/GEMCUT/GEMCUT.HTM

Is that the sort of info you were looking for?

BTW, I'm glad you had some CZ's to share with your students - better diamonds than CZ's, if you're going to have cut stones flying around your classroom!

 

[ponyrider]

Yes! That is the kind of info and the links I was looking for. So the facets are only on the outside of the stone? I am off to do some learnin' (says the old cowgirl)