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There are many different metals and
alloys
used in modern jewelry making.
The two precious metals most often
used are alloys of silver
and gold.
The type of jewelry you can wear is
not
just determined by your wallet -
but also
by the way your body reacts to
and
tolerates exposure to metals.
Sterling
silver tarnishes, especially in hot,
humid
weather. It contains 7.5%
copper by weight,
which reacts with common air
pollutants,
darkening the
surface of the metal.
This can
prompt skin irritation
if your skin is sensitive
to (usually) nickel or (sometimes) copper.
If you have noticed that you have an itch that
persists with drying and reddening
of your skin
where your jewelry touches it,
you are probably
sensitive to the alloy
in the metal.
Gold and silver
are known to be non - reactive
metals; but that does
not
mean that everyone
can wear any type of
gold or
silver jewelry
without any problem.
Understanding
more about metals can help you
to choose jewelry
that is more comfortable and
healthy for you to wear!
Higher karat gold alloys tend to be better
tolerated
than lower karat
qualities
because there is less of the
reactive metal
in the alloy.
Many people wear 18K or
22K gold jewelry for this reason.
Sterling silver is .925 pure, or 92.5% silver by
weight,
a very high percentage.
Most people
don't have any
problems wearing
sterling silver jewelry.
Modern silver
alloys don't contain nickel, the usual
irritant in jewelry
metals.
Lower percentage silver alloys
like vintage "European"
silver
can irritate
your skin
more easily than sterling silver jewelry
if you have copper
sensitive skin,
because old European silver
is .800 fine,
or 80% silver / 20% copper.
Following is a listing of metals commonly
used in jewelry
making and an explanation
of their properties.
GOLD ALLOYS
Pure 24K gold
is hypoallergenic.
It doesn't cause
irritation to the body.
However, the metals
mixed with gold to make it
harder or
enhance the color of gold can cause
adverse
skin reactions.
Gold alloys are available in many colors.
The color of the
alloy is
determined by
the
percentage and type(s) of metal
"mixed" with
the pure gold.
Rose gold contains more copper; until
recently
white gold was
traditionally made with
nickel.
Now it is also made with palladium,
a
platinum family metal;
green gold is made with
an alloy of fine silver.
There
are MANY other
combinations. The
percentage of gold used is
directly related
to the karat content of the alloy.
It does not matter what type of metal
is "mixed"
with the gold, just how much.
The chart (right) shows how much
gold is in your jewelry.
In this chart, "alloy"
means the
other metal.
It can be silver,
copper, zinc,
nickel,
iron
or almost any other metal.
For instance, 10 karat yellow gold is
41.67% pure gold and
58.33%
"other metals",
mostly copper, maybe some silver
and most
likely some
nickel or zinc to add hardness.
In the United States gold must be
at least 9K
to be sold
as karat gold.
Lower karat gold
alloys have a
higher
percentage of the other
metals
added to them.
They tend to
react to
the
pollutants and other
impurities
in
the air faster
than higher karat gold alloys.
This means that the high percentage of
copper
or other
metal in
the lower karat alloy will
tarnish
(or
oxidize), just
like sterling silver items do.
This can occur especially in
hot weather when
the metals react to salt
in
perspiration.
If this happens to your sterling silver or
lower karat gold
jewelry,
you may want to
take it off and wash the piece
in hot
water with
a
detergent like Dawn, Joy or whatever
you prefer.
If your
jewelry is really
dirty, try scrubbing
it carefully with
a soft toothbrush. Polish with a jewelry
polishing cloth,
if you have one.
Rinse and dry before wearing.
If you have a problem with
sterling silver, medium to
low karat gold
will
probably give you difficulties as well.
Medium to low karat gold has a
higher
percentage of copper in it than sterling silver.
Nickel allergies are the most common. Many people have
problems
wearing
white gold -
the problem isn't the gold.
It's actually nickel - the alloy - that causes skin reactions!
The new
palladium white gold alloys are a
bit more
expensive, but are hypoallergenic.
SILVER ALLOYS
Sterling silver is generally used
for jewelry, and that
is
what most people think of
when they see silver.
Silver also comes in various
quality grades,
measured by
1/1000 parts per gram.
There are impurities that naturally
occur in silver at the
molecular level. These impurities consist of other metals -
usually copper,
but traces of
other metals can also be found.
These trace impurities are insignificant,
and would be
too costly to remove - so .999 silver is considered pure.
The table (at right) shows the
types of
silver alloys
generally
used in jewelry making.
All the alloys shown are legally
referred to as "silver".
The only legal requirement is
that they are
quality stamped or marked for sale to the public.
As with gold, silver in its
fine state is a non - reactive
metal -
allergies are possible but VERY rare.
People who have problems wearing
silver jewelry
are
usually
allergic
to the copper in the alloyed metal, not the silver.
During the European
Industrial Revolution,
people found
that
their .800 silver
was tarnishing much faster
than before -
a reaction to
the new pollutants in the air - from burning
coal in the factories!
Fine, or pure, silver with no
copper content
does not tarnish easily - it can get dirty, of course.
There is a
new alloy called Argentium®
Silver. It is sterling,
but
contains germanium in place of copper.
Argentium®
doesn't develop
firescale as easily
during soldering and doesn't tarnish the way
traditional sterling silver does.
Plated and Filled
There are different grades
and methods of
bonding
precious metals
to a less expensive
base metal, as indicated in the chart at the right.
Many jewelry items are made of
either plated or filled
metals.
This is done to keep the cost
of these items as low as possible.
The whole piece,
as with a chain, or in many cases,
the clasp
and
metal parts of
an otherwise top quality gemstone
bead necklace or bracelet.
If it is taken care of and worn properly, such as over a sweater, a necklace
with plated parts can last for
a very reasonable length of time,
even years -
but eventually the plated
metal parts will oxidize or the plating will wear
through to the base metal.
Filled metals are much higher quality.
They have one or
more layers of
precious metal bonded to a base
with
heat and pressure.
Filled materials are at least 1/20 precious metal by weight.
They are much longer lasting
than ordinary plated objects.
Filled metal objects are marked with a
quality stamp,
such as 12k GF or 14k GF.
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