Platinum 900/950 + Iridium

[knowverylittle]

Does anyone know the pro and cons of alloying with Iridium v''s other alloy mixes. Some sites proclaim that ''cheap'' Internet vendors all use Iridium which result in a soft metal. Is this true?

In general is 950 more expensive than 900 and are there any benefits to 95%?

 

[knowverylittle]

More Googling found this post by http://www.mwmjewelry.com/ (amazing work, probably way out of my price range):


Cobalt platinum is quite hard and can be brittle. This is the reason that it scratches easily. When Plat cobalt is scratched, the metal will flake away as gold will. The other platinum alloys will scratch but when they are scratched,the metal is displaced, not flaked off of the object as with gold or the cobalt alloy. It is used by manufacturers because it casts well and because it does not resist abrasion as the other platinum alloys do, it is easier to polish after casting. The cobalt metal is not a good mix to try to fabricate or stamp due to it's brittleness. Forget about welding it too.

Cobalt by itself is dirt cheap. This is another strong reason for manufacturers to use it. Iridium is quite expensive and ruthenium, I'm told, requires special alloying techniques - but that's hear say.

950 iridium platinum is quite soft, casts and fabricates well. It stamps well. I find it too soft for most applications.

900 iridium platinum, while much softer than the cobalt alloy, is harder and less likely to ding than 950 ir - especially if it is fabricated from drawn or rolled stock - or die struck as was often the case in day past. It also casts well. Great stuff to work with but doesn't meet the coveted 950 purity so often demanded here and mandated over seas. This will scratch but as in all but the cobalt mx, the metal stays on the piece and doesn't flake away.

950 ruthenium platinum is quite hard and more resistant to dinging than either iridium alloy but it is also quite resistant to wear/abrasion which makes manufacturing and polishing this mix more difficult due to increased finishing time over the cobalt mix. I do fabrication and casting in this mix periodically.

Typically, I use a mix of 950 pt, iridium and 950 pt, ruthenium because it feels and works like 900 pt, iridium but maintains the 950 (Plat) standard. It is difficult and time consuming to polish - bad for me. It is highly resistant to wear - good for the consumer. It will scratch but the metal, as I mentioned previously, is moved, not lost - good for long life of a cherished piece.

So does anyone know the benefit of 950, other that it consisting of more platinum.

 

[caratgirl]

Speaking as a consumer, I've had both 950 platinum alloyed with ruthenium and 900 platinum alloyed with iridium. I found the ruthenium alloy to be more grey. Also, even though most jewelers wanted to steer me away from the iridium alloy, I tried one piece and it's been love ever since. It is much whiter and I have found absolutely no difference in the wear or scratches. I don't know if I've just had good luck with the manufacturers that I have chosen, but the three rings I have in the 10% iridium alloy wear great and look much whiter.

 

[knowverylittle]

It is too late for us anyway as I already ordered a 950 [5% Ir] setting. From lack of replies and not finding anything on the web I am assuming that the only benefit to 95% over 90% is snob value.

Do you know why Jewelers were trying to put you off iridium? I find it strange no vendor has posted anything about it one way or the other.

 

[caratgirl]

The funny thing is, they said it takes a better polish, but it is slightly softer, so will scratch more. I have found the opposite to be the case, so I am thinking some manufacturers work harden the metal better than others.