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White Gold - Platinum Group Metals
By:
Peter Roberts
Sometimes this is called white gold.
Platinum is not just one metal, however - which (to me at
least) still strikes me as strange. We are talking alloys,
however, so maybe its no more strange than the allows we have
of gold. Be aware that when you talk platinum you may
be a number of different combined metals.
The metal(s)
are collectively denser, rarer, and hence more expensive, than
gold itself. What makes it popular for setting
gemstones is that it holds them more securely in a setting,
and its rich white color can be used to full effect in
showing off gems (there is no potential minor clash of colors
like with gold, in other words)
The European standard
marking of Platinum is PT950, or 950, whilst in the USA (to be
different I guess!) its PL or PLAT.
So what are these
various metals that we all call platinum? Osmium
(Os)
Osmium/platinum alloy is usually used for standard
weights - so I guess you won't see it much on rings. It is a
bluish-white color, and quite brittle. Iridium
(Ir)
The alloy, usually about 10% iridium with 90%
platinum, is a very hard, white and brittle metal
(which is an interesting contrast to Gold which is extremely
soft) and is much harder than pure platinum. Palladium (Pd)
(or White Gold)
Now we are onto something. This is
relatively rare and soft, with a white silvery color.
It is alloyed for jewelry, with gold, and commonly called
white gold. Rhodium (Rh)
This is a
white silvery color, used to plate agent
platinum and white gold to create a
white, durable, hard coating. Ruthenium (Ru)
Its
claim to fame is being highly resistant to wear and can be
found in jewelry. It is a grayish-white color.
Copyright Peter Roberts - http://ringssites.biz
 
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