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Platinum Alloys - Ruthenium vs Cobalt?

swaye2010

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I would like to hear some opinions on different platinum alloys. What I am looking for is a ring that is hard wearing and will show the least amount of scratches. I am not a jeweler but I have been working with one in Sweden. I understand that there is a Vickers hardness rating to the different alloy combinations but I don’t really know what these means as a consumer. I am in the US, and most of the platinum rings I have had made are PT950 w/ 5% ruthenium. I have also had some rings made in China that I am told are PT950 and palladium. These rings did not have pave and I noticed that they scratch very easily over a short period of time. The jeweler in Sweden says Iridium is a banned alloy there and suggest cobalt for making my ring. It will be a 3 stone ring with hand engraving over the outside and inside of the shank and no pave.

I don’t really know a lot about this and I was wondering if anyone had opinions on cobalt as an alloy. I have read through the pricescope info and a couple threads but they were quite old. I would love to see some rings with the PT950 & cobalt alloy combination. I hear they can be more grey then PT950 and ruthenium.

Any guidance would be appreciated!
 

Karl_K

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Many benchmen refer to platinum/cobalt as butter.
It shoves around just like butter and holds a polish just as well.
 

swaye2010

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Thank you for your response Karl. Do you feel it holds up as well with a hand engraved ring like PT950 & ruthenium? I don’t think I have ever seen a PT950 & cobalt ring in person. It gets confusing when designing in different countries.
 

Karl_K

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Thank you for your response Karl. Do you feel it holds up as well with a hand engraved ring like PT950 & ruthenium? I don’t think I have ever seen a PT950 & cobalt ring in person. It gets confusing when designing in different countries.
950plat/ru is a lot more abrasion resistant than 950 plat/co or worse 900plat/co.
950 plat/ru is a lot trickier to work with than most other platinum alloys so some do not like to use it.
I would stick to 950 plat/ru or 900 plat/ir
 

swaye2010

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I was told it was banned because it is known to cause cancer. I haven’t looked into this myself but having lived there before, they seem to ban many things deemed unsafe that are still used in other countries.
 

Winks_Elf

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I've heard this about cadmium, but not iridium. I've read about platinum, iridium, and ruthenium as well as gold being used to treat cancer though.
 

OoohShiny

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Nothing really on good ol' wikipedia about health affects of iridium - it seems fairly inert!

https://en.wikipedia.org/wiki/Iridium

Precautions[edit]
Iridium in bulk metallic form is not biologically important or hazardous to health due to its lack of reactivity with tissues; there are only about 20 parts per trillion of iridium in human tissue.[13] Like most metals, finely divided iridium powder can be hazardous to handle, as it is an irritant and may ignite in air.[45] Very little is known about the toxicity of iridium compounds, because they are used in very small amounts, but soluble salts, such as the iridium halides, could be hazardous due to elements other than iridium or due to iridium itself.[28] However, most iridium compounds are insoluble, which makes absorption into the body difficult.[13]

A radioisotope of iridium, 192
Ir, is dangerous, like other radioactive isotopes. The only reported injuries related to iridium concern accidental exposure to radiation from 192
Ir used in brachytherapy.[28] High-energy gamma radiation from 192
Ir can increase the risk of cancer. External exposure can cause burns, radiation poisoning, and death. Ingestion of 192Ir can burn the linings of the stomach and the intestines.[84] 192Ir, 192mIr, and 194mIr tend to deposit in the liver, and can pose health hazards from both gamma and beta radiation.[43]
Interesting that it's very rare, though!

Iridium is one of the rarest elements in Earth's crust, with annual production and consumption of only three tonnes
Iridium is one of the nine least abundant stable elements in Earth's crust, having an average mass fraction of 0.001 ppm in crustal rock; gold is 40 times more abundant, platinum is 10 times more abundant, and silver and mercury are 80 times more abundant.[6
 

swaye2010

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Thanks for the info. I just want to leave one more comment after going back and forth through language and time changes in Sweden. There was a misunderstanding about the alloy and what they were actually talking about was ruthenium and not iridium. This is what the fabricator they used said:

“I have heard of platinum ruthenium. That alloy is widely used in the United States from Tiffany and other big companies, because it's a good cast material. Unfortunately, that alloy has a dull "aftertaste", because ruthenium is a cancer-inducing material and therefore has not got its breakthrough in Europe.

There are no risks for the wearer of platinum ruthenium jewelry, but there are no studies until now about ruthenium not released by melting and how, for example, slip dust affects the health of those who work with the material.”

I have never spent a lot of time thinking about alloys as almost all the pieces of jewelry I have had made in recent years has been done by the same company in LA and I know they use PT950/Ru. I have only been mildly interested as of late because I had some pieces made in other countries and I realized that different countries favor different alloys. I was surprised by what they said about ruthenium in Sweden as I thought it was still in the platinum family. As I mentioned before, they do have a tendency to ban or not use things they feel may cause public or employee health issues.

I don’t know a lot about the fabrication process but I do know that working with platinum/ruthenium alloys takes some skill and higher melt points (based on what I have read). I am curious why cobalt has not taken off more in the USA for women’s platinum jewelry if it is like ‘working with butter’ and has a similar Vicker hardness rating? Is the color more off putting? I have a hard time trying to find any real life examples on google. Most of what comes up are men’s cobalt bands and I would really like to see what a completed e-ring would look like. The company is willing to make it for me in PT950/Ru from their fabricator so I will get what I want but I appreciate any trade input.

This is not the company I am buying the ring from but they are one of the largest fine jewelry companies in Sweden and they talk about how their platinum is alloyed with cobalt. They also mention Wolfram but I have no idea what that is??

https://vanbruun.com/eu/guide/rings/platinum
 

OoohShiny

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Perhaps 'wolfram' actually means 'tungsten', as per the pie charts further down the page??

I think something is lost in translation! lol
 

Karl_K

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Vickers hardness is only one of many things that makes a good material for a ring or not.
It is how much a diamond pin goes into the material for a given amount of force.
More important for rings is abrasion resistance and resistance to bending while not being brittle.
950 Plat/ru beats all but the rarely seen and expensive heat treatable alloys in doing that. 900plat/ir is close behind.
Plat/cobalt is not as good at doing that.
 
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motownmama

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I’m forgetting the original alloy Brian Gavin used for my 3 stone ring, but it was WAYYYYYY too soft for me. I had it remade and they used 950/RU. I recall it had to be sent out. Complete difference in wearability. It’s like a tank now.
 

Karl_K

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I’m forgetting the original alloy Brian Gavin used for my 3 stone ring, but it was WAYYYYYY too soft for me. I had it remade and they used 950/RU. I recall it had to be sent out. Complete difference in wearability. It’s like a tank now.
The fumes from melting RU are very toxic so pretty much everyone sends it out to large casting houses.
 

holeydonut

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I’m forgetting the original alloy Brian Gavin used for my 3 stone ring, but it was WAYYYYYY too soft for me. I had it remade and they used 950/RU. I recall it had to be sent out. Complete difference in wearability. It’s like a tank now.
I asked about this with a BGD rep for a platinum setting from the Brian Gavin Collection that I'm ordering from them. They claim to use 950 Platinum / Ruthenium on their in-house bench for his Collection settings.
 

motownmama

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My ring was originally alloyed with Iridium - too soft. Had it changed to Ruthenium. If that's what they're using for you - GREAT!
 

Johnbt

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"Perhaps 'wolfram' actually means 'tungsten'"

It does. If you look at the Periodic Table of the elements, atomic number 74 is Tungsten and the symbol is W... for Wolfram... the earlier Germanic name for it.
 

cflutist

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My four HPD custom rings are all Pt/Ru as is my Vatche ring. Tiffany's also uses Pt/Ru.
Yes, there are some scratches and dings, but that is from wearing them daily.
 

DAF

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I've heard this about cadmium, but not iridium. I've read about platinum, iridium, and ruthenium as well as gold being used to treat cancer though.
Gold compounds (gold salt) have also been used to treat Rheumatoid Arthritis and other autoimmune diseases.
 

LightBright

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My ring was originally alloyed with Iridium - too soft. Had it changed to Ruthenium. If that's what they're using for you - GREAT!
My understanding is that 950 platinum 50 Iridium is soft. 900 platinum 100 Iridium is almost as hard as 950 platinum 50 Ruthenium, which is the hardest of all. See link that MollyMalone posted above, on durability of the various alloys from Mark Morrell who uses exclusively 900/100 Plat Iridium.

http://www.mwmjewelry.com/platinum_purity.htm
 

LightBright

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The fumes from melting RU are very toxic so pretty much everyone sends it out to large casting houses.
Hi Karl, this is why I’m personally concerned about the move towards exclusive use of Ruthenium alloys instead of Iridium James Allen, Vatche, BGD, Tiffany, use 950 Plat/Ruthenium alloy. Whiteflash, David Klass, Gabriel and Co, A Jaffe, Mark Morrell use 900/100 Plat/Iridium alloy.

My concern is a move towards a toxic substance that could harm workers if not carefully controlled. I also wonder if the use of Ruthenium in rings might somehow cause this metal to be absorbed by the body ( I have no idea about this, but know for example that metals like copper are absorbed through the skin). Sweden just may be in the vanguard of better consumer and worker protections...
 
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OoohShiny

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"Perhaps 'wolfram' actually means 'tungsten'"

It does. If you look at the Periodic Table of the elements, atomic number 74 is Tungsten and the symbol is W... for Wolfram... the earlier Germanic name for it.
Interesting!

That is the one new thing I've learnt today :))
 

swaye2010

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I am coming back to one of my own old thread’s to ask again about platinum alloys. I happen to love platinum rings and I love the durability and even the patina of having a PT950 & Ruthenium alloy. I know from a durability or wear perspective there is not much difference to the PT900 & Iridium used by some high end designers. It is just not an alloy mixture that is used in Europe I think due to hallmarking issues (but I could be wrong?)

Back to my original thread - the ring I had made late last year in Sweden did end up being cast in PT950/Ru after it took some time to find someone in England to actually cast it for us. I really didn’t want to use cobalt which seems to be a standard for platinum rings in Sweden. I am actually having a few more rings cast right now and I find the process of making the rings kind of fascinating. I love having miligrain & hand engraving or full pave on my rings as I am pretty hard on them. The rings that I have had for many years now show no signs of wear and I know they will certainly last for at least my lifetime.

This time around my rings are being cast in a 3D printer using PT950 & Ruthenium. Don’t know much about the actual process with casting but I have asked for pictures so I can see what it looks like. When discussing metal alloys this time around, I was told about a new platinum/Gold/Iridium combination from a German company. I wasn’t ready to test it out on the rings I was working on but I wondered if anyone has seen this in jewelry or worked with it already? I am not even sure how it is hallmarked (PT/AU)?

Here is the company info I was sent to read about it:

https://www.platingold.com/en/startseite/

Here is a picture of the ring made in Sweden and the ring on the right made in LA both in PT950/RU and before & after it started to patina. They both actually look closer in finish now as the mirror finish has dulled a bit with the ring on the left.

7B16B277-9F75-4387-A77A-DC2AA81AF973.jpeg
 

muesli

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Hi! I'm going to revive this thread as I'm in Sweden and are going to get a ring in platinum/ruthenium (from the US).

After seeing this thread I'm a bit worried that if I might need to resize it further down the road it could be problematic getting it done here.

I've contacted a goldsmith and are awaiting their reply on the matter, so we'll see.

Maybe it's better to go with the 900/ir alloy (if possible)?

TIA
 

swaye2010

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Hi! I'm going to revive this thread as I'm in Sweden and are going to get a ring in platinum/ruthenium (from the US).

After seeing this thread I'm a bit worried that if I might need to resize it further down the road it could be problematic getting it done here.

I've contacted a goldsmith and are awaiting their reply on the matter, so we'll see.

Maybe it's better to go with the 900/ir alloy (if possible)?

TIA
I don’t think it is a problem getting something sized. They should be able to do it. I believe that PT900/IR is only used inside the US. I know they didn’t use it when I also lived in England but it could have changed. I still prefer platinum/ruthenium over the one with cobalt. I really think you will be fine.
 

muesli

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I don’t think it is a problem getting something sized. They should be able to do it. I believe that PT900/IR is only used inside the US. I know they didn’t use it when I also lived in England but it could have changed. I still prefer platinum/ruthenium over the one with cobalt. I really think you will be fine.
Thank you so much! I'll solve it if I ever need to get it resized, I just like being a bit prepared.

Tusen tack ännu en gång:).
 
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