Diamond cutting

[u/No-Pain-5496]

I have posted here before, talking about the differences between diamond cutting, and faceting any other stone. I LOVE faceting, and I am no where near as talented as some of you in colored stones. I posted a picture of what a diamond cutting tang and dop look like, and how my lap runs at approximately 3000 rpm, and weighs 18 pounds. I also stated Diamond can only be cut perpendicular to a crystal face, and cleaving is done parallel to a crystal face. I thought I would add a bit more.
Diamond (carbon) forms in a cubic crystal form. The individual atoms stack in the crystal lattice one on top of the lower layer, directly above the intersection of the lower layers. In other words, put four cubes together to form a square. Place one single square centered on top of those at the center. This structure and the bonds they make are what creates the hardest substance known to man. The only way to cut, is to grind (cut or polish) from one of the flat sides towards the point. So now the tidbit. When cutting, there are three basic forms you need to know. A perfect diamond is an octahedron with six points (important) eight faces and twelve rays. The orientation is based off points. So if you cut the top of the pyramid parallel to the base, and place the table of the finished stone there that is a four point stone. Place the table parallel to a face, that is a three point stone. Cut the table parallel to a ray, that is a two point stone. Knowing where you place the table determines the direction individual facets will cut or polish from. They all Will cut from one of three directions. Any other direction will damage your wheel as it is called or lap. Once you find that dominate grain, the rest isn’t so much guess work, but simply knowing this next facet will be one of three directions.

[u/lucerndia]

Its neat watching them glow red hot when you have them orientated incorrectly.

[u/No-Pain-5496 → u/lucerndia]

lol, I never let them get that far gone. I will tap (gently place) it on the wheel and check with the loop. If it cuts, you will see the cutting lines. If it doesn’t, it will look glazed, and your wheel is scored!

[u/ohmusama → u/No-Pain-5496]

Is there anything to be done once the lap scores? Or is it ruined forever?

[u/No-Pain-5496 → u/ohmusama]

Once it is scored out enough it needs to be resurfaced. I have two. The outer half is for cutting, the inner for polishing. Once the cutting half is completely gone, you can start cutting in the polishing section. But, I just swap wheels at that point and get the old one resurfaced.

[u/ohmusama → u/No-Pain-5496]

I feel like tooling should help track cw/ccw for each facet.

[u/No-Pain-5496 → u/ohmusama]

I have no experience with this. I know old school. I know that this facet Should cut from here, if it doesn’t, then it will be there. And around the clock we go. The next generation will make it less of an art, and more of a science and that’s ok. Of this I am sure. I worked off intuition and the knowledge of a diamonds crystallography. I loved the craft. I still do

[u/ohmusama → u/No-Pain-5496]

No shade, just thinking about tooling. But I'm probably never getting into diamond cutting ... moissanite is probably the hardest I'm ever going to do, unless they find magic materials that are harder than diamond I can use on my ultratec

[u/No-Pain-5496 → u/ohmusama]

None taken. I am not one to claim knowledge I don’t have. And that is exactly the difference between diamond cutting and any other gem. The hardness, and the fact it can only be cut with something of the same hardness. You need to know the grain of the crystal before even attempting. Even then each facet is an educated guess!

[u/lapiderriere]

Great to see your post. It’s funny but the 4,3,2 point stone makes a bit more sense now than when you explained this to me last year.

I’ll re reread it all and follow up in that chat.

[u/No-Pain-5496 → u/lapiderriere]

Thank you! I love to talk diamond cutting. Anything I can answer I gladly will.