Cleaning Gemstones & Organics
AGATE - You can remove dirt and grease by dabbing
with a cotton pad dampened with warm soapy water. If the dirt's
stubborn, gently rub in the soapy water with a soft toothbrush.
Dab off with clean cold water and dry immediately with a soft cloth.
Don't try to achieve a shine by vigorous rubbing; clean agate is
supposed to have a slightly waxy luster.
AMBER - Same as agate, but revive the sheen with
almond or olive oil on a cotton pad, then wipe off the excess and buff
with chamois leather. NEVER soak amber in water or it will get a cloudy
look that's almost impossible to remove. Also avoid contact with
alcohol, mineral spirits, perfume and hair spray, which will permanently
dull the stones.
AQUAMARINE - NEVER use hot water, which can crack
the stones. Clean with lukewarm soapy water and a clean cotton
rag, then rinse with clean water and use a soft cloth to dry and buff.
CAMEOS & INTAGLIOS - These can of course
be made of all sorts of substances, so treat them conservatively or see
a pro. It's safe to dust them with soft make-up brushes and clean
really dirty ones with warm soapy water on cotton pads.
CARNELIAN - Same as agate.
CORAL - Remove dirt with cotton pads or a small
artist's brush dipped in warm soapy water. Stubborn marks can be
removed by brushing on a thin creamy paste of water and crocus
powder. Finish by using pads or brush to rinse with clean water,
then dry with a cotton rag. Some say never soak coral in water,
but I've also heard the color of vintage coral beads can be revived
by soaking in salt water, which makes sense to me.
BOTTOM LINE: It's your call. Clearly
salt can be injurious to metals, so at least keep clasps out of brine.
DIAMOND, GENUINE - If genuine diamonds are
just slightly dirty, wash in warm soapy water and rinse with clean cold
water, then dry thoroughly. Remove grease and heavier dirt
deposits with a small artist's brush dipped alternately into denatured
alcohol and ammonia, then dab dry with a soft cloth.
DIAMOND, ARTIFICIAL - NEVER wash artificial
diamonds, as these are often glued in and can be dislodged from
their settings when wet. When cleaning artificial diamonds with
alcohol, blow to evaporate excess liquid as rapidly as possible.
EMERALD - Use a small artist's brush to apply warm
soapy water with two drops of ammonia. If dirt is stubborn, dip
the same brush in denatured alcohol. Gently buff with chamois
JADE - Put two drops of ammonia into warm soapy
water and wipe with absorbent cotton, then rinse with a cloth moistened
with clean water, dry with a soft cloth and buff with a chamois.
To clean crevices, use a stiff-bristled artist's brush. For very
stubborn dirt, dampen brush with denatured alcohol or mineral spirits.
JET - Gently rub with soft bread to clean.
MOTHER-OF-PEARL - Milk is the cleaning liquid of
choice for mother-of-pearl. Dab it on with a soft cloth, then dry
and buff with another.
ONYX - Same as agate and carnelian.
OPAL- When opal jewelry needs cleaning, place it
along with a handful of powdered magnesia or potato flour in a glass jar
and gently shake for three minutes, then leave for 24 hours.
Repeat the process, then shake again, remove the jewelry and dust off
excess powder with a soft dusting brush.
PEARL, NATURAL OR CULTURED - Same as
opal. Carefully avoid contact with perfume, hair spray,
alcohol, mineral spirits and abrasive substances. If you wear your
real pearls seldom, sleep in them occasionally; I'm told they need skin
contact and warmth to keen the sheen alive. (I also enjoy wearing
mine when I swim in the sea, though I suppose the clasp hates it.)
PEARL, ARTIFICIAL - Moisten chamois leather
with water and wipe.
RUBY - Dip cotton pads in warm soapy water to
clean, then rinse with clean water and dry with a soft cloth. Rub
gently with chamois leather moistened with alcohol.
SAPPHIRE - Same as ruby
TURQUOISE - Same as agate, carnelian and onyx.
Crystals (Glass & Rhinestones)
If open at
back: It's generally safe to wipe with a small
amount of glass cleaner on a cotton swab.
and/or foiled at back: Avoid moisture of any type, with can
result in "dead" stones and/or dislodge stones from settings.
If unset (like
beads) : Gently wipe surface with a minimal amount of
glass cleaner on a soft cloth or cotton pad.
Never wash rhinestones with water!
Stubborn stains can be removed with oxalic acid, which is poisonous.
To produce this at home, boil rhubarb leaves and stalk tops in water
(wearing your face mask, rubber gloves and goggles). Dab a cotton
pad in the liquid and apply it to the stains, leaving the pad in place
for 5-10 minutes. Naturally keep children and pets away from the
scene of such activity.
It's much safer to see a professional.
BRASS - You can
remove minimal tarnish with a commercial brass cleaner and polish with a
soft-lint-free rag. If obstinate marks remain, mix a little
kerosene with jeweler's rouge and a few drops of ammonia to form a thick
creamy paste and apply gently with a rag until marks disappear.
For heavier tarnish, mix a tablespoon each of salt and vinegar with a
cup of hot water and gently apply with the finest grade steel wool
before washing with warm soapy water, rinsing with cold and drying
immediately with a soft towel. For severe tarnish, the
electrochemical dip described for silver can be used (but never mix
metals in the same dip).
BRONZE - Because
much of the value of old bronze lies in its patina, treat this with
great care. NEVER use abrasive powders. You can safely dust
bronze with a soft-bristled brush and moisten it with mineral spirits to
remove dirt and grease from recessed areas. If they
must be washed, dry them immediately with soft toweling.
Green patina can safely be deepened with a touch of neutral shoe polish,
according to my antiquities dealer. A fine white microcrystalline
wax such as is used to finish leather may be applied if the metal was
CHROMIUM - If the
plating is just dirty, wash with lukewarm soapy water and a soft cloth,
rinse with clean water and dry thoroughly with a soft towel. Add a
few drops of ammonia to the soapy water if the chromium is discolored.
Stubborn reddish-brown rust spots (from oxide) can be removed by gently
applying a commercial chrome polish with a soft cloth in accordance with
the maker's directions, then finish by buffing with a small quantity of
chrome polish on a soft cloth.
COPPER - Either
follow the instructions for brass cleaning or use the chemical dip
described for cleaning silver (never mixing metals in the same dip).
If there's verdigris and you're sure you don't want the blue-green
patina, small areas can be removed with a paste of white vinegar and
salt, gently applied with a cotton pad and washed away with water.
More extensive patches of verdigris can be treated by sponging on a
solution comprised of one tablespoon of lemon juice in a cup of warm
distilled water and then rinsing -- first with warm soapy water and then
with clean warm water. Always dry copper thoroughly after
cleaning. You can protect the surface with a thin coating of
microcrystalline wax such as is used to finish leather.
GOLD - Chains and
areas that collect dirt can be cleaned with a stiff-bristled artist's
brush. Warm soapy water can also be used when gold gets dirty or
greasy. Follow with a rinse in clean cold water, dry thoroughly and
buff with dry chamois leather. Naturally watch out for the hot tub
and swimming pool to avoid damage and loss.
IRON/STEEL - Both
these metals are prone to rusting, so try to catch rust's development
before pitting sets in. At the first sign of a reddish-brown
tinge, treat the metal with rust remover or wipe it with a brush soaked
in kerosene, then rinse with mineral spirits and dry thoroughly with a
towel. Use microcrystalline wax to protect against further
corrosion. If the metal is pitted already, don't try to grind it down;
all you can safely do is brush off the rust and treat it as described.
IVORY & HORN -
Wipe with absorbent cotton dipped in warm soapy water, rinse with cotton
and clean water and dry with a soft towel. Almond oil can be
gently rubbed in with a soft cloth to revive surface sheen.
LEAD - The
blue-gray-green patina of valuable old lead is easily destroyed.
You can safely clean the surface with a stiff-bristled artist's
brush, but don't risk doing more.
Steel) - To remove surface discoloration, dampen a clean cloth with
water and use it to pat baking soda on. Rub gently over the
marcasites. Be sure to dry thoroughly with a soft cloth.
PEWTER - To
preserve the patina of old pewter, limit cleaning to dusting with a
soft-bristled brush and then gently rubbing with clean chamois leather.
If salts have formed spots on old pewter, see a professional; cleaning
will require the use of dangerous chemicals.
PLATINUM - To
remove discoloration, add a little olive oil or denatured alcohol to
jeweler's rouge to make a creamy paste and rub it on with a clean soft
rag, then wipe off and buff with another rag.
SILVER - First
wash in hot soapy water, using a soft-bristled brush on dirty recessed
areas, then rinse and dry with a soft towel (unless silver is set with
stones that hate water). Next, assess the degree of tarnish (brown
or purplish silver sulfide deposits) on the surface. Light tarnish
can be removed with a silver cloth, but more serious tarnish will
require a paste or liquid. If tarnish is advanced (and especially
if base metal is showing), an electrochemical dip will be required.
When pieces are plated, do realize you lose a minute layer of silver
every time you use an abrasive substance. It's far better to use
the cloth often or resort to the chemical dip (a rather complex process
I'll detail in the next newsletter).
TORTOISESHELL - Same procedures apply as for
ivory and horn, but add a little microcrystalline wax to the almond
oil and buff with another cloth.
REPAIR TIPS: Scratches can be removed by
applying a creamy paste of denatured alcohol and crocus powder with a
dry chamois. Melt matching wax crayons to mend and fill cracks.
metal decorated with chasing (small grooves produced by punches,
chisels and other small tools) will occasionally need to be
cleaned to remove grime from the hollows. Use a soft-bristled
brush such as a baby's toothbrush, moistened with mineral spirits.
ENGRAVING: First examine etched metal with a magnifying glass.
If the edges are breaking down, take the piece to a professional for
cleaning; otherwise, clean both etched and engraved metals with
a small artist's brush dipped in the cleaning-polishing agent
specified for the metal in question. Buff thoroughly to remove
all polish, or it will quickly attract more dirt.
VERMEIL - If
gold-washed silver pieces require more than dusting with a soft-bristled
brush, be sure use a silver cloth marked "safe for gold" or
the gilding will rub off.
Soft enamels wash out of settings easily, so
dampness must be avoided at all cost. Moisture can activate acid
and salts that can corrode copper settings and displace enamel.
Hard enamels may withstand gentle hand cleaning, but why risk it?
BOTTOM LINE: Don't try this at home, Kids; enamel
is too easily damaged. The same goes for collectible
coins and medals, as well as damascened and niello pieces.