Determining Platinum Content and Marks
Posted: Saturday, September 01, 2007
by Bo Carpenter
Pandora Bracelets USA
Platinum is
a rare precious metal that is used to create fine jewelry. Its heavy weight and durability make it a
metal that will not wear away with constant use.
When used as
prongs and other setting components, platinum holds fine gemstones firmly in
place for the life of the jewelry.The metal's natural white luster provides a
rich backdrop for diamonds.
In addition,
it's a metal that's just as elegant when used all by itself to create a piece
of jewelry, either a simple polished item or a design with engraved motifs.
Platinum
also looks stunning when mixed with contrasting touches of 18K yellow gold.
The
Platinum Group of Metals and Platinum Marks
There are
six related metals belong to the Platinum Group of Metals: Platinum, Iridium, Palladium,
Ruthenium, Rhodium and Osmium.
Jewelry can
contain different percentages of pure platinum. The US Federal Trade Commission, FTC, publishes
guidelines for acceptable marking standards for platinum jewelry sold in the
U.S.
Platinum
content is usually expressed as the amount of pure platinum the jewelry
contains in parts per thousand. For
example, mix up a huge bucket of fruit juices that contains 1,000 ounces--900
hundred of the ounces are plain apples and 100 are pears. That makes the apples
900 parts per thousand of your mix.
Another way
to express this is as follows: the apples make up ninety percent of the
mix--900 divided by 1000. Jewelry that contains at least 950 parts per thousand
of pure platinum may be marked or described as "Platinum".
Jewelry that
contains 850, 900 or 950 parts per thousand of pure platinum may be marked
"Plat" or "Pt" if a number is used in front of the term to
disclose the amount of pure platinum in the mix, such as: "850 Plat"
or "850 Pt", or "950 Plat" or "950 Pt" .
Jewelry that
contains at least 950 parts per thousand of platinum group metals, with at
least 500 parts per thousand of the total pure platinum, may be marked as
platinum as long as the numbers of each metal are disclosed.
For example,
"600 Pt. 350 Ir." or 600 Plat. 350 Irid." indicates an alloy
that is 600 parts pure platinum and 350 parts iridium. "550Pt. 350Pd.
50Ir." or "550Plat. 350Pall. 50Irid." indicates an alloy that is
550 parts pure platinum, 350 parts palladium and 50 parts iridum. Ask your
jeweler to explain platinum content and markings if you are not sure which
combination is the most suitable for your jewelry purchase.
Bo Carpenter writes for Lewis Jewelers. Lewis Jewelers is
proud to carry the full line of Pandora Jewelry. For more information, contact
Lewis Jewelers at 877-88-LEWIS or visit http://www.LewisJewelers.com/pandora_bracelets/ or http://www.lewisjewelers.com .