Ether (was Chemicals - shelf-life?)

In normal jewellery making you are unlikely to come across or need
diethyl ether, commonly referred to just as ether. Apparently
though it has some gemological applications (what?). It is often
encountered in laboratories where it can be useful for cleaning and
especially degreasing. It is very volatile and makes a vapour which
is heavier than air, can flow a long way from, say, a spill, and can
be very easilly ignited … a small spark from static electricity in
clothing will do it. This flammability is normally the greatest
hazard associated with ether. Try not to get it over your hands too
much either, as it really degreases your skin.

There is another hazard, which is very real, though not so often
encountered. During prolongued storage ethers (there are many) can
form another material called peroxide (and there are many of those
too). The peroxide formed in diethyl ether (“ether”) can explode
rather easilly, but it isn’t usually concentrated enough to cause
concern. Conditions which encourage its formation include contact
with air and exposure to light. Unfortunately it is very much less
volatile than ether though, so will tend to become more concentrated
when ether evaporates. Again, in small quantities this isn’t a
problem, but, as in the instance mentioned, any old, partly full
container should be treated with suspicion. Copper reduces the rate
of peroxide formation, and so containers of ether are often sold with
a little piece of copper gauze in the bottom … this should be left
in place.

There are chemical techniques to remove peroxide from ether, and in
those circumstances it can be safely distilled, for example to
recover clean material from dirty solvent washings, but this isn’t
the forum to discuss those methods, and anyone using ether in a
gemological investigation or for other purposes should regard it as a
single use material, unless working in a laboratory with safe
established recovery and re-use procedures.

Kevin (NW England, UK)

Kevin,

   In normal jewellery making you are unlikely to come across or
need diethyl ether, commonly referred to just as ether.  Apparently
though it has some gemological applications (what?). 

Thank you for your as well, and to answer the above
point:

The main use is for helping to distinguish between amber and copal
resin. There may be more sophisticated ways of detection these days,
but it used to be and is still helpful in separating the two. The
surface of amber remains unaffected whilst copal, due to its more
recent formation, becomes tacky. If you check in most amber detection
chapters of the various books you will most likely find reference to
this very topic. Nowadays with infra-red etc… it may not be used on
such a regular basis, but that is usually why ether is around in a
laboratory.

Hope that helps a little.
Regards - Nick

Now I see. Although I have not tried any of this (so it’s just a
theory) I would imagine that there are any number of other much less
hazardous organic solvents that would do the job just as well.

Margaret