Was: Is using tourist gold flakes a flaky idea?
Very interesting. OK how do they get opals that thin for triplets?
I used to have an annular saw at work (when I worked as a
microscopist) that was ideal for cuting thin opal slices. You
encapsulate the opal in polyester resin and then cut slices of
0.5-1mm thick. An annular saw has a very thin blade that has its
cutting edge on the inside and was supposed to be used by us for
making wafers for fluid inclusion studies of geological samples or
for slicing semiconductor materials for either TEM study or FIBSIMS.
Another way is to mount the opal on the backing material and then
slice off the excess material with a thin bladed diamond saw and
then repeat with the offcut. A micrometer crossfeed is required and a
slow blade speed.
With the Spencer Idaho Opals that I was taught on we ground down to
the color and epoxied on a optical Quartz cap, then with a trim saw
cut very close to the color line, any excess material left was then
ground off with a flat lap. Next a backing material-black basenite
(very fine grained basalt) was epoxied in place, and the whole
assembly trimmed to size and the quartz cap domed and polished as a
Thank you. I have always wondered about that since I first accidentally had one come apart and saw how incredibly thin they were. Still seems almost impossible to do it without them disintegrating.
I think you will find that a lot of triplets are just slices of Opal that were too thin to be set without backing and a cover to protect it , I cut opals and some times you get thin pieces like that