The Professor from Periodic Videos is at it again. Alrosa let him handle some huge diamonds, including a few lovely coloured ones and he explores fluorescence again. He discusses types of cut briefly. We also get to see the cutting room, a close look at how a lapidary works at his bench and how lasers are used to quickly cut off large sections of unwanted gemstone material.
I was surprised to see that the laser leaves a black surface on the stone on the face it cut. But I should have expected it as a laser works by burning material. The diamond material, where the laser cuts, is converted into graphite by the heat. It really does generate a lot of heat, so water has to be directed onto the cutting surface to cool the stone, otherwise the diamond itself could ignite. That water, of course, then needs to be cleaned of graphite and re-cooled so it can be recycled. I don’t know why they don’t just dispose of the used water and use fresh, cold water for diamond cutting. Maybe it’s special water?
A huge pink diamond is showcased throughout this video. It seems Alrosa is expecting to sell it for some $tens of millions. It certainly is beautiful. There is also a big purplish pink diamond and a bright yellow diamond, which are also valued by Alrosa around the $10 million range.