The zircon grain mounts were finally set in epoxy! Here are some photos.
You’ll remember from the last update that the zircon crystals are placed on double-sided tape into rows within a 1-cm circle. Once that’s done, a glass ring is placed around the grains and then a plastic ring goes over that. Then the epoxy is poured into the plastic and glass rings until the whole thing is covered.
Once the epoxy sets, the puck is removed from the rings and the zircon grains are embedded within the epoxy. The pucks are about an inch tall and have the diameter about the size of a quarter.
The next photo shows the grains set in the epoxy still within the glass ring. The next step will be to polish down the zircon grains until the center of the grains are exposed. This is why the grains are sized, thicker grains take more polishing than thinner grains. If you have multiple sizes of grains then you might polish away some grains and not polish others enough.
The polishing is all done by hand, without even a polishing turntable to help! The process is similar to creating thin sections. A series of increasingly smaller grit sizes are used to grind away thin layers and polish for a nice reflective surface.