Eternity Band - Ideal Platinum Alloy

[bps413]

Hello - looking for some experts to weigh in on platinum alloys. I’ve seen a lot of posts about the ideal platinum mixes - 90/10 IR and 95/5 RU. Most of the posts I’ve seen seem to be geared toward engagement rings and all metal jewelry.

I’m curious if 95/5 IR is still considered “less desirable” for something like a 3/4 eternity band?

 

[Karl_K]

yes, even more so.
5% is not enough IR

 

[bps413]

yes, even more so.

Thanks for your input. To confirm my understanding, is that because the softer alloy is more malleable and thus, prone to bending? If so, probably not what you want in something holding multiple tiny diamonds!

 

[Karl_K]

Thanks for your input. To confirm my understanding, is that because the softer alloy is more malleable and thus, prone to bending? If so, probably not what you want in something holding multiple tiny diamonds!

Its more complex than that, surface hardness, bending resistance, not to brittle, can it take a fine finish, castability, workability and many other factors go into determining if an alloy is a good ring alloy.
Experience has shown that 950ru and 900ir have a better balance of those qualities than many other alloys including 950ir.

 

[bps413]

Its more complex than that, surface hardness, bending resistance, not to brittle, can it take a fine finish, castability, workability and many other factors go into determining if an alloy is a good ring alloy.
Experience has shown that 950ru and 900ir have a better balance of those qualities than many other alloys including 950ir.

I appreciate you educating me. Thanks for the great info!

 

[diamondyes]

Not to thread jack, but does anyone know much about colbalt platinum?

 

[Karl_K]

Not to thread jack, but does anyone know much about colbalt platinum?

yes, enough to say run away from it.
It has a high surface hardness but moves like butter.
The color is bad compared to other alloys.
It is sometimes used for casting because it casts very well not needing a lot of work afterwards so it is cheaper to make.
When it does need work its a problem because it does not work well.

 

[Karl_K]

Also cobalt fumes or dust exposure has been linked to early onset dementia.

 

[yssie]

What style will the eternity be?

I had a U-prong in 14k WG. Never had any issues whatsoever. Had the exact same ring remade with very slightly larger stones in platinum (950/Ru) and now have to be very vigilant about checking for loose stones (and have had to have prongs tightened multiple times).

Platinum deforms inelastically whereas 14k/18k gold tends to “try to snap back into place”. On the flip side - gold will break with less sudden force than platinum. These behaviours are somewhat dependent on method of manufacture but generally… The truisms are takehomes. You’ll often hear that platinum is stronger, that’s because for something like a multi-pronged head holding a single stone, if that head gets whacked you’d rather it just go out of shape and keep holding that stone than have prongs break off… But for something like an eternity with smaller prongs, prongs that are feeling constant pressures from your finger flexing but that are unlikely to individually sustain sudden strong impacts, white gold’s tendency toward elastic deformation is actually preferable and “stronger”.

For a channel or bezel set band the difference is less meaningful IMO.

I’ll be having my platinum U-prong remade with white gold one day. I miss having it be a carefree piece.

 

[RunningwithScissors]

I love threads like this. I learn so much from PS!

 

[michkal]

Not sure if you’re open to white gold, but when I got my eternity band last year, WG was recommended for the reasons mentioned above. I chose it because it seemed better for stone security. Mine is white gold/palladium. No problems so far and I’m not that careful with it.

Editing to add it’s a u prong eternity with a sizing bar, so kind of in between a 3/4 and a full.

 

[diamondyes]

What style will the eternity be?

I had a U-prong in 14k WG. Never had any issues whatsoever. Had the exact same ring remade with very slightly larger stones in platinum (950/Ru) and now have to be very vigilant about checking for loose stones (and have had to have prongs tightened multiple times).

Platinum deforms inelastically whereas 14k/18k gold tends to “try to snap back into place”. On the flip side - gold will break with less sudden force than platinum. These behaviours are somewhat dependent on method of manufacture but generally… The truisms are takehomes. You’ll often hear that platinum is stronger, that’s because for something like a multi-pronged head holding a single stone, if that head gets whacked you’d rather it just go out of shape and keep holding that stone than have prongs break off… But for something like an eternity with smaller prongs, prongs that are feeling constant pressures from your finger flexing but that are unlikely to individually sustain sudden strong impacts, white gold’s tendency toward elastic deformation is actually preferable and “stronger”.

For a channel or bezel set band the difference is less meaningful IMO.

I’ll be having my platinum U-prong remade with white gold one day. I miss having it be a carefree piece.

How enlightening! Would this logic hold true for this style of eternity?

 

[yssie]

How enlightening! Would this logic hold true for this style of eternity?

Matters much less since the stones aren’t relying on long prongs holding their shape exactly

 

[diamondyes]

Matters much less since the stones aren’t relying on long prongs holding their shape exactly

Ok that confirmed my suspicions but I still appreciate all the extra info! I’m always on team platinum but I’m trying to expand my mind to consider that white gold might have a place in my life haha