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Billings
10-23-2008, 08:11 PM
Do different blends of platinum have different looking colors? I know there are three different types of gold that come from different mixtures of metals. Is there something similar to this with platinum?

rodman86
11-05-2008, 07:59 PM
The three most common "blends" of platinum, are as follows;
- .999 (999/1000 parts platinum, 1/1000 part alloy) used for platinum coins and bullion
- .950 used for jewelry

Due to the very...very...very...small amount of alloy that has been mixed with the platinum there is very little (if any) difference in color.

Compared to the most common karatages of gold;
- 1.00 = 24k
- .917 (22k)
- .750 (18k)
- .585 (14k)
- .417 (10k)

24k gold is extremely yellow and when less gold is used, and more alloys are added, the color begins to darken (place a piece of 10k gold next to a piece of 22k or 18k and you can see a distinct difference.

Billings
11-07-2008, 10:25 AM
Thanks for the information.

Do you by any chance know what most platinum alloys are? For jewelry, is there an "industry standard" or something similar?

Yosef
11-07-2008, 11:58 AM
For the fabrication of jewelry, most platinum alloys are either:
950 (95% pure)
925
900

Often the alloying metals are either:
Ruthenium
Iridium
Cobalt

Same goes for palladium alloy blends.

Some rings that are not cast (such as the Henrich Denzel rings we sell) are actually made of forged platinum that is 950 blended with 5% Tungsten. This gives a very hard alloy and will be tougher then most white gold blends. Cast Pt/Ru (platinum/ruthenium) has a vickers hardness of around 120, compared to 450 with Pt/W (platinum/tungsten).

Billings
12-08-2008, 05:32 AM
Yosef,

There was a post on here today about Rhodium and I was wondering if stuff like that is ever mixed in with Platinum.

Thanks

Yosef
12-08-2008, 11:16 AM
Rhodium is a very rare metal, even much more rare then platinum, so it's very costly. It's only used to plate jewelry, not to alloy, as far as I know.

Some platinum jewelry is rhodium plated, although I don't personally think it's necessary. rhodium is slightly more white then platinum, but it's such a minor difference.... Platinum and palladium are still top white metals. The whitest metal is actually silver but it tarnishes. If one wanted to alloy platinum with a whiter metal, it would make sense to use silver instead of rhodium.