Hi All,
Recently I took in a ring for routine cleaning and polishing. Ring
is gold with small emerald and two small diamonds. On close
examintion it seems the wearer must have been working with silicone
cement of some kind because it was imbedded behind all the stones.
Ultrasound didn’t work, digging it out with a needle was difficult.
Wondered if there is a better way - some kind of solvent perhaps?
Herb
digging it out with a needle was difficult. Wondered if there is a better way - some kind of solvent perhaps?
Herb; Don’t even think about putting an emerald in to a solvent,
Many Many Emeralds are oil treated , even putting one in an ultra
sonic cleaner or under steam cleaner is most dangerous. These can
severely damage the stone; Emeralds are sometimes made from a doublet
similar to the way some Opals are done. Besides there aren’t many
solvents that are damaging to silicone, One! The most dangerous thing
that would dissolve the silicone would be Petrol, Or as we so fondly
refer to it Regular Unleaded Gasoline, Diesel Fuel will also soften
the silicone but both are Known Carcinogens, One is extremely
combustible, and the other smells nasty and it doesn’t come off if
your skin very easy!!. I know because that and Motor oil mixture are
what I use in my larger lapidary saws, , So given the choices, I
would suggest that you might want to use a Bamboo Skewer, and go
after the gunk or what ever it is. The Bamboo skewers can be found at
most food markets, or if you are fortunate in your back yard, Very
Handy things and they shouldn’t damage your emerald much more than it
has been. Good luck and breathe very easy on your Emerald
Kenneth Ferrell
Ultrasound didn't work, digging it out with a needle was difficult. Wondered if there is a better way - some kind of solvent perhaps?
Hello Herb, If by ‘ultrasound’ you mean ‘ultrasonic’, you’ve already
taken a big chance and have been lucky indeed as most emeralds are
oiled or epoxy treated, often before leaving the mine. There are
many types of oils used to treat emeralds, and practically all of
them will be removed or dissolved by solvents such as acetone or
alcohol. Ultrasonic cleaners will also loosen and remove these oils,
and possibly widen those likely-to-be-present, often
surface-reaching fractures that all but the finest emeralds have.
Kenneth hits the nail on the head by suggesting you use a bamboo
skewer or other device that would be softer than the beryl you’re
scraping. And it’s not simply a question of using something softer
than the gem material itself, it’s also a question of the emerald’s
actual clarity. Most emeralds have at least some fractures, and most
have fractures that reach the surface. Also, if the stone in
question has been treated with a colored oil or other treatment,
those fractures are even less apparent to the untrained eye, as the
colored oils and resins tend to reduce the visibility of the
fractures. Be very careful. Breathing carefully in SoFla,
James S. Duncan, G.G.