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Metals Glossary
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METALS GLOSSARY
Gold
The word gold,
used by itself, means all gold or 24 karat (24K) gold.
Because 24K gold is soft, it's usually mixed with other metals to increase its
hardness and durability. If a piece of jewelry is not 24 karat gold, the karat
quality should accompany any claim that the item is gold. White gold is yellow gold with some white
metals mixed to alter its color. Pink
gold contains more copper to create pink.
The karat quality marking tells you what proportion of gold
is mixed with the other metals. Fourteen karat (14K) jewelry contains 14 parts
of gold, mixed in throughout with 10 parts of base metal. The
higher the karat rating, the higher the proportion of gold in the piece of
jewelry.
Most jewelry is marked with its karat quality, although
marking is not required by law. Near the karat quality mark, you should see the
name or the U.S.
registered trademark of the company that will stand behind the mark. The
trademark may be in the form of a name, symbol or initials. If you don't see a
trademark accompanying a quality mark on a piece of jewelry, look for another
piece.
Solid gold refers to an item made of any karat gold, if the
inside of the item is not hollow. The proportion of gold in the piece of
jewelry still is determined by the karat mark.
Jewelry can be plated with gold in a variety of ways. Gold
plate refers to items that are either mechanically
plated, electroplated, or plated by any other means with gold to a base metal.
Eventually, gold plating wears away, but how soon will depend on how often the
item is worn and how thick the plating is.
Gold-filled, gold
overlay and rolled gold plate are terms used to describe jewelry that has a layer of at
least 10 karat gold mechanically bonded to a base metal. If the jewelry is
marked with one of these terms, the term or abbreviation should follow the
karat quality of the gold used (for example, 14K Gold Overlay or 12K RGP). If
the layer of karat gold is less than 1/20th of the total weight of the item,
any marking must state the actual percentage of karat gold, such as 1/40 14K
Gold Overlay.
Gold electroplate describes jewelry that has a layer
(at least .175 microns thick) of a minimum of 10 karat gold deposited on a base
metal by an electrolytic process. The terms gold flashed or gold washed
describe products that have an extremely thin electroplating of gold (less than
.175 microns thick). This will wear away more quickly than gold plate,
gold-filled or gold electroplate.
Platinum, Silver and Other Metals
Platinum is a precious metal that costs more
than gold. It usually is mixed with other similar metals, known as the platinum
group metals:iridium,
palladium, ruthenium, rhodium and osmium.
Known as the King of jewelry until World War I when need for war
efforts.
Different markings are used on platinum jewelry as compared
with gold jewelry, based on the amount of pure platinum in the piece. The
quality markings for platinum are based on parts per thousand. For example, the
marking 900 Platinum means that 900 parts out of 1000 are pure platinum, or in
other words, the item is 90% platinum and 10% other metals. The abbreviations
for platinum - Plat. or Pt. - also can be used in
marking jewelry.
Items that contain at least 950 parts per
thousand pure platinum can be marked simply platinum. Items that have at
least 850 parts per thousand pure platinum can be
marked with the amount of pure platinum and the word platinum or an
abbreviation (for example, 950 platinum, 900 Plat. or 850 Pt.). Jewelry that
contains less than 850 parts per thousand pure platinum, but has a total of 950
parts per thousand of platinum group metals (of which at least 500 parts is
pure platinum), may be marked with both the amount of pure platinum and the
amount of the other platinum group metals in the piece. For example, the
marking 600 Plat. 350 Irid.
means that the item has 600 parts per thousand (60%) platinum, and 350 parts
per thousand (35%) iridium, totaling 950 parts per thousand of platinum group
metals, and 50 parts per thousand (5%) other metals.
The words silver or sterling silver describe a product that
contains 92.5% silver. Silver products sometimes may be marked 925 which means
that 925 parts per thousand are pure silver. Some jewelry may be described as silverplate: a layer of silver is bonded to a base metal.
The mark coin silver is used for compounds that contain 90% silver. According
to the law, quality-marked silver also must bear the name or a U.S. registered
trademark of the company or person that will stand behind the mark.
Vermeil (ver-may),
a special type of gold plated product, consists of a base of sterling silver
that is coated or plated with gold.
Pewter items may be described and marked as
such if they contain at least 90% tin.
Palladium ---- Exciting, attractive,
economical and resurfacing after 50 year absence into the 21st
century jewelry market. It weighs a
little less than 14kt. white gold and a lot less than platinum helpful when
cost of metal is connected to weight. Never
needs rhodium
plating like white gold to shine. Harder to polish than white gold by said to
be hypo allergic unlike issues with white gold alloys.
Information provided by Federal Trade Commission’s Website
entitled Protecting the Consumer. www.ftc.gov
