Copper / Platinum alloys

[tanalasta]

I know about the common platinum alloys such as ruthenium/iridium...

But does anyone have experience working in 97% platinum / 3 % copper alloy?

More importantly, what is it's overall appearance in a ring and does it take a polish (or even rhodium plating) well?

Does it scratch easily?

Cost?

 

[strmrdr]

http://www.platinummetalsreview.com/dynamic/article/view/49-3-110-117

 

[strmrdr]

use the search feature on that site and search for copper it brings up a bunch more info.

 

[JohnQuixote]

Date: 1/30/2007 2:19:38 AM
Author:tanalasta

I know about the common platinum alloys such as ruthenium/iridium...

But does anyone have experience working in 97% platinum / 3 % copper alloy?

More importantly, what is it's overall appearance in a ring and does it take a polish (or even rhodium plating) well?

Does it scratch easily?

Cost?

Some platinumsmiths use copper because it is nice to work with. It oxidizes a little and has a somewhat different color if you can see the difference (that may be the reason for the 3% you mentioned, rather than the more common 5% mix).

As for cost, well it's >95% platinum.Expect to pay a platinum price.

People try out new alloys all the time with hopes of getting certain properties. The variations depend on what effect the jeweler is trying to achieve.For example, platinum-ruthenium has the highest melting point of common platinum alloys but it's it is harder and crisper at the bench.Platinum-iridium has a lower flow point and is fabulous for casting and gemstone setting but it’s more difficult to hand-tool (Iridium is like copper, but white).

In many commercial situations you may find that salespeople may not know what alloy was used for a specific piece; simply that it's platinum, gold, WG, etc.After 95% or higher platinum alloys can be marked simply PLAT.Mass-producing casting houses often use Plat-Cobalt whereas independent designers and custom jewelers make use of many different alloys; typically what’s most appropriate for their purposes.After the metal is poured there’s not much to distinguish one alloy from another.The last little portion is a point of interest but it's really up to who is producing and manufacturing the piece to know what's most appropriate.That’s is why it’s important to work with reputable companies and craftsmen.

Here’s a thread with some discussion:

https://www.pricescope.com/community/threads/common-alloys-used-in-jewelry.55281/