Laser sawing allows fashioning
shapes and facet combinations than were not seen a generation
ago.
Cutting diamonds is rather ingenious. Since diamond is the hardest material man has known for centuries, how do you cut one?
Answer: With another diamond.
Actually, the cutting is done with diamond powder, which is applied to a cast iron wheel, often as a slurry with olive oil.
The cutter must study the rough diamond carefully in order to position the crystal properly.
Once he decides on the correct orientation for the rough, he secures it in a "paw", or holder. The soft direction of the crystal face he is planning to cut will be aligned to the rotation of the wheel.
The particles of diamond on the wheel coincidentally align in virtually every direction. So some of the particles hard direction will be "cutting" against the diamond's "soft" direction