Ammonite Polishing

I found an imperfection in the cap on an ammonite doublet freeform
and decided that I had nothing to loose, so I tried to polish it out.
I was able to remove the imperfection using fine sand paper and
tripoli polish. Unfortunately I ruined the “glossy” surface of the
cap. If I wet the ammonite, it looks great, but as soon it dries out,
the surface gets hazy and the iridescence of the ammonite does not
come through. I tried to fix this with both red rouge and green
rouge, but neither helped.

I always thought that these ammonites were capped with quartz or
something similar, but the cap on this one seems more like a
polymer/plastic. When I was sanding and polishing, I smelled
something like burnt plastic.

Can anyone suggest how I can clean this up and make this nice
ammonite brilliant again?

Regards
Milt Fischbein
Calgary, Canada

    Can anyone suggest how I can clean this up and make this nice
ammonite brilliant again? 

The new UV curing crystal cement is great for this. Unlike epoxy, it
can be polished with normal metal or plastic polishing technique.
Layer a coat on top and polish it lightly until you get what you
want.

A story about this stuff: About two years or so ago, I was building
an opal/ diamond pendant in 22K. I dropped the opal into my benchpan
and it broke, nearly in half. I was sick. I was devastated.
Unbelievable. Beautiful opal. Trashed in 1/10 of a second. A reminder
to lay a towel across the tools in my pan for protection. Too late.
I really thought this job might be the death of me. I told the
client. He wasn’t interested in a new stone. He was more interested
in trying to restore his little treasure. I mapped out a strategy to
epoxy it back together and to use crystal cement to hide the damage.
He agreed. I finished the job and delivered it fully expecting to
recieve no compensation. The damage was only visible under
magnification. He was so happy, that he paid fully for the job.
I was a happy boy.

The new UV curing crystal cement is great for this.

Would you please give more details on this product? Is it a
cyanoacrylate type glue? jim

Some years ago I was involved in a pilot plant which was evaluating
a new process for producing methyl methacrylate monomer (the monomer
for the trade name plastics “Lucite” and “Plexiglass”). A lab
technician made a large sphere with a flat bottom by polymerizing
the monomer from the pilot plant in a cut off Florence flask. I had
a large piece of pyrite that was placed in the center of the sphere.
I remember that he said he polished it with talcum powder. Is
anybody familiar with talcum powder as a polishing agent for "soft"
plastics? Talc is a basic magnesium silicate with a hardness of
one. The massive form of talc is soapstone. Black soapstone was
the material of choice for laboratory sinks, bench tops, tables,
etc. The material seemed to be a lot harder than one!

Captain Blood
"Marlinespike Seamanship in Precious Metals"
@Alden_Glenda_Blood

You could try polishing the cap with Fabulustre (Rio carries it)
with a cotton wheel on your foredom. I polish my watch crystal with
it often and it seems to work well.

Lisa Hawthorne
@Lisa_Hawthorne