Dear Orchidians: I just purchased a few pieces of partially-cut and
finished ammonite and could use some advice from the lapidaries in
the group. I don’t normally buy anything like this, but got lots of
ideas the second I looked at them, and couldn’t resist. I would like
to trim off the rough edges a little, and bring them to a higher
polish. I will describe them, and perhaps you can advise me. I have 3
pieces, each with 3 trimmed, straight, and smooth sides, and one
rough, thinner, irregular edge. I would like to trim/sand this edge
and make it more bezel-“settable”. 1 piece is about 5 mm thick; 1
about 4 mm, and one 3 mm. I don’t know what the matrix is; it’s dull
grey and slaty-looking. The tops have been polished to about 600 or
800 grit, to guess by appearances. The fossilized layer appears
quite thin (no surprise). They have gorgeous blocks of bright
orange, dark red, and green colors. Given the thinness of the fossil
layer, how can I polish these? I am a non lapidary. I have the usual
metal-working tools, including flex-shaft, polishing tools and
wheels, diamond tools, sandpaper, etc. If I need to order any
special discs to do this, I will. I assume also that I will need to
protect the stone with something when I have polished it, as all the
ammonite I have seen finished were triplets with quartz caps.
Apart from quartz caps, which is beyond my capacity, what could I
use? Would a clear epoxy resin work?
Thanks very much for the advice!