It's kind of hard to get closer to a 2mm subject! That is a scan, and I have experimented with making a larger image, but all that really does is make the appearance of their size confusing. They are half-domes of dichroic glass (quality CBS) which are made by scoring and hand-clipping...a whole lot of work! I guess you can call them 'cabs' but I associate the term with an item that is focal to a work; these are really accessories.
KellyK