Platinum Alloys - Ruthenium vs Cobalt?

[swaye2010]

Du ar valkomen!

 

[tenshix]

Bumping this topic to ask if anyone has any experience on what you personally see for color difference between 950 Plat- 50 Ruthenium, 950 Plat- 50 Cobalt, and 950 Plat- 50 Iridium?

I have a worn Pt950-Ru band from Tiffany’s that has patina from 3 years of wear but looks whiter/light grey compared to my brand new Pt950-Co band. The Pt950-Co metal is giving off warmth from what I’ve observed and even though the stone quality is the same, it’s making the diamonds on the Pt950-Co band appear to be one or two color drops from an F.

It’s really difficult to capture on camera so I’m reluctant to post because I can’t tell the difference in the photos or video but I’ve asked my hubby and friends in person if they see any differences in color and both confirmed the Pt950-Co band diamonds look warmer for them too. It’s more obvious when I put them side by side/stacked on top of each other but you do have to really look at it.

This is the case regardless of the lighting setting or day/nighttime from what I’ve observed.

I was just wondering if anyone has had a similar experience and that my eyes aren’t playing Jedi mind tricks on me, haha.

 

[Karl_K]

Yes. there is a color differece between the different alloys.
There are even differeces with the same alloy.

 

[tenshix]

Yes. there is a color differece between the different alloys.
There are even differeces with the same alloy.

Oh wow! There’s still a difference in color even if it’s the same alloy mix?

In a lot of the sites I’ve read on seems like the color difference range seems to be darker grey to light grey but I’ve never seen anyone mention warmth..

Is this something you’ve seen at all in Pt950-Co alloys?

 

[Karl_K]

Oh wow! There’s still a difference in color even if it’s the same alloy mix?

In a lot of the sites I’ve read on seems like the color difference range seems to be darker grey to light grey but I’ve never seen anyone mention warmth..

Is this something you’ve seen at all in Pt950-Co alloys?

No 2 batches of alloy even from the same caster are ever the same, then you have contamination in the mixing and casting and polishing stages as well as differences in finish causing an apparant color difference.
There are a lot of variables.

I dont have a ton of experience with pt950-co but I would not say its impossible.
Given how easy it is to feel the weight difference between plat and 18k if you have had some of each, I'm not going to suggest its wrongly marked.
So im going to leave it as its not impossible.

 

[swaye2010]

Are you sure it is not unplated white gold? That can have warmth show up in the color. In the US, they seem to use cobalt in bands but not as much for e-rings. When I lived in Europe though, it was much more common. I think on the first page I had a picture of two rings that were made with PT950/RU but by different companies and the colors were vastly different.

 

[tenshix]

By the weight of the ring it feels like platinum to me but I can’t be sure unless I somehow get it tested but I’m not sure what my options would be.

The hallmark inside says PLAT.

Regarding the stone warmth I spoke to another jeweler on the phone and they suggested I unmount at least one diamond to test. However I just got the ring so I’m again reluctant to have it be taken apart and tested immediately. Which is why I was wondering if Pt-Co warmth was a possibility and could affect the color of the stones.

I think I will have to bring it in person to a jeweler to see how they would test for these things.

 

[diamondseeker2006]

By the weight of the ring it feels like platinum to me but I can’t be sure unless I somehow get it tested but I’m not sure what my options would be.

The hallmark inside says PLAT.

Regarding the stone warmth I spoke to another jeweler on the phone and they suggested I unmount at least one diamond to test. However I just got the ring so I’m again reluctant to have it be taken apart and tested immediately. Which is why I was wondering if Pt-Co warmth was a possibility and could affect the color of the stones.

I think I will have to bring it in person to a jeweler to see how they would test for these things.

The diamonds shouldn't change color because of the metal. It sounds more like the diamonds are lower color than the other ring.

 

[tenshix]

The diamonds shouldn't change color because of the metal. It sounds more like the diamonds are lower color than the other ring.

That’s what I’m suspecting as well.. But it’s difficult for me to prove the color difference to the seller unless I independently get it tested for sure.