On Wed, 22 Oct 2008 22:20:45 -0700, in rec.crafts.jewelry "Sterling"
wrote:


Thanks Peter, for the info. I've googled this cleaning process for silver and have read where some
believe it wont harm the softer stones, and others believe it does so I came here for the definitive
answer. I just wanted to be able to offer my customers a way to clean the silver in their jewelry
without harming the other components or stones.

Safely cleaning jewelry:

For the most part, most jewelry can be safely cleaned. Professionals usually
use either or both, a steam cleaner and/or an ultrasonic cleaner. These have
the advantage of being very fast, and very thorough. Both, however, have limits
and pitfalls.

Steam cleaners can subject more brittle stones to heat shock, which can fracture
or break some of the more fragile ones. Some opals, amber, some peridot, or
other highly heat sensative stones might be at risk. Usually this can be done
anyway, by holding the item well below the steam jet, raising it up as needed,
to make the temperature change gradual. The main danger with steam cleaners
is simply blowing out stones that aren't tight and secure. Marcasites, tiny
seed pearls, other glued on rhinestones or pearls, or almost any small loose
stones, including diamonds, can be at risk here. Common sense tells you whether
to use such a method.

Ultrasonics, while fast, are also sometimes actually quite aggressive. Softer
metals, including cast silver, can have their polish actually damaged, and a few
softer stones can be as well, though it's not so common that it's the ultrasonic
itself that damages stones. Usually it's too aggressive a cleaning solution,
especially those with ammonia, which can harm a few stones (notably amber), or
stones which have been coated or waxed. Like steam cleaners, ultrasonic
cleaners are wonderfully effective at finding ways to remove any stone that
isn't securely set. At least with the ultrasonic, if a stone falls out, you've
got a decent chance of finding it simply by cleaning out the tank. Steamers
tend to blow tiny stones around the room when they unset a small stone... In
both cases, properly set stones aren't loosened or removed.

The main dangers in cleaning stones is simply that some cleaning solutions can
damage some stones. The big danger, for example, with tarnex, the silver
tarnish remover, is that it's acidic. That can damage pearns, or carbonate gems
like coral, mexican onyx, malachite, lapis, and a few others. It's not a
function of the hardness of the gems, but rather whether they are affected by
acids.

Similarly, a few stones can be affected by harsher alkaline cleaning agents. The
two main ones are amber, which as an organic resin, is actually attacked by
ammonia or strong alkali cleaners, (so can be jet, a form of coal not commonly
seen these days), and turqoise, which because it's porous (in lower quality but
genuine versions, as opposed to the plastic filled treated material that's
actually pretty safe to clean), can absorbe soaps, cleaners, and other
chemicals. These can change the color over time, generally from blue to
greenish. Some lower quality coral can also sometimes be attacked by strong
alkali cleaners, though it may be that wax coatings are what are actually being
attacked. Jewelry using wood as a decorative element also has to be cleaned
with care, for similar reasons. While many jewelry cleaners say not to use
them on pearls, in truth, it's not actually the pearls that are endangerd by
stronger cleaners, but rather the cords they are strung on. The pearls
themselves are sensative to anything acid, but soaps, detergents, and alkaline
cleaners used appropriately won't hurt the pearls themselves. But
traditionally, pearls are strung on silk, and the cleaning solutions soak into
the strand inside the drill hole, and aren't rinsed, so they can rot the silk
strand over time. But pearls glued to posts on gold or silver jewelry don't
have this problem, and are generally safe to clean in non-acid cleaners.

For those stones, like turqoise, that need gentle cleaning, the trick is simply
to make sure your cleaning solution is itself not full of dirt already, and is
simply a gentle detergent, like dish washing detergent. Rinse clean after
cleaning, and things are fine. Same with the other more fragile stones.

The washing soda or baking soda method of cleaning tarnish from silver is even
gentler than any normal detergent. You're not going to be damaging much of
anything with baking or washing soda solution... Things glued, especially with
epoxy might be an exception if left to soak for very long times, since some
epoxies and glues are not water resistant. The soda has no effect, but the
water itself can degrade some glues. But we'd be talking much longer times than
what would be used to clean tarnish from silver.

For general cleaning of jewelry that has more durable stones, if you don't have
the pro equipment, the easiest is to mix up a solution of hot water with a good
strong household cleaner (Mr. Clean, Simple Green, Top Job, etc). Even better
if it has some ammonia in it. About the same strength you might use to clean
the kitchen floor is about right. put it in a saucepan on the stove to simmer,
and hang the gold or platinum jewelry in it on hooks over the side of the pan,
which you can make from paper clips bent open. Allow to simmer in there for
five or ten minutes, which loosens the gunk behind diamonds or other gems,
allowing it to simply rinse clean. Or fill a jar with the same solution, only
don't bother to heat, and soak over night. Rinse in the morning.

After cleaning, always use a pin or sharp tweezers or some sort of point to
gently check that stones are still tight and don't rock or jiggle when gently
probed.

How NOT to clean jewelry....

Toothpaste is abrasive. Don't use it on soft stones or polished metal. It
WILL put a low matte semi bright sheen on silver that's already worn, but be
careful not to use it on still polished metal, especially in areas that you
can't polish again if you wished to, such as those nice prepolished areas inside
prong settings on gold or platinum jewelry that were polished before the stones
were set. Those areas get dirty, but don't loose their polish. No toothpaste.
The soft toothbrush is OK, though.

If using a hot or simmering cleaning solution, don't go straight from that hot
condition to a cold water rinse. Some stones can be cracked that way. Likewise,
for more fragile stones, don't go straight from cold into a boiling hot
solution...

No bleach. Not ever. It damages some stones, and makes of mess of silver
(unless you WANTED a sort of junky grey dull yucky surface...), and attacks some
gold alloys, especially white golds. Ammonia is safe in most jewelry cleaning
tasks. Bleach is not. And NEVER mix the two (generates toxic chlorine gas)

Peter