Making a crystal glass - GIF

[nova_robotics]

Woah woah woah. I need know what every step of that process was. They're cutting slices off some giant nugget? I have never seen that before. Then to form it they turn it down on a lathe? Then they use some magic boring bar to instantly polish the surface?? This is all crazy to me and a huge departure from the glass blowing that I would have expected to be used as a manufacturing process. Is that perhaps some sort of quartz?