# Platinum jewelry



## Husker (Jan 20, 2009)

What is the percentage of Platinum in common rings (wedding sets, etc)?

Is it 90% platinum? Or is it usually something higher than this?

Jim.


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## Lou (Jan 20, 2009)

It really depends on the jeweler--some use 90/10 PtIr, some use 95/5 Pt/Ru. Pure platinum is very soft and is hardly ever used. 

There are numerous jewelers on this forum that will have more info than I.


Lou


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## Husker (Jan 21, 2009)

Lou (or anyone else who knows),

What is the common platinum percentage in platinum dental work? 

Also, would bending without breaking and strong magnet having no attraction be a simple field test to help eliminate many non-platinum white dental alloys, prior to doing a more intensive testing? 

I seem to remember reading somewhere that white dental alloys that bend and do not snap, are almost always worth checking out. It would be nice to have some idea on what types of alloys are to be expected an tested for, before taking a plunge into these waters. I would never buy without adequate testing (prelim tests, my electronic test, and then AR/stannous). The biggest problem I foresee, is if there are multitudes of allow percentages, quickly in the field determining what the allow percentage is. Dental gold is the same way. It is alloyed differently than jewelry, and throws field testing equipment off. I simply pay at 16K, and it comes out close enough, when all is said and done.

Jim.


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## Lou (Jan 21, 2009)

Not all (or even most) of those dental alloys are magnetic, even if they are completely lacking in noble metals. 

If they bend but don't snap, are heavy, are fairly gray, and they don't oxidize when you put a flame to it (the worthless stuff will turn colors and oxidize), then it is most likely a Pt/Pd alloy with other stuff like Ru, Ag and perhaps a little gold in it.

As for the common platinum percentage in dental work--that's anybody's guess because there are so many varieties. Dental gold is a good example--I've seen anything from 12K to the normal 16K to little pennyweights of 24K. It depends on the manufacturer, its grade (I-IV) and intended use.


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## Irons (Jan 22, 2009)

PGM alloys will glow white hot when put into a reducing flame. Try it on a known bit of Pt wire to get a feel for it.
Pt alloys have about twice the density as Pd alloys, so that will give you a hint.


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## grainsofgold (Jan 26, 2009)

If the jewelry is older, 1970's and prior usually it is 90% plat 10% irrid if its was made in USA.

If the piece is older and European it may have plat and copper with it

Generally after the 1970's you will find a mix of 90 plat/10 irrid and a many varieties of 95 % plat with 5% irrid, ruthenium and some with cobalt-

For a piece to be legally stamped PT , it must contain at least 95% pt. Many manufactures started playing with mixes that would cast better with fewer problems- The main solution was adding cobalt. Cobalt make the metal more fluid when cast but it causes other problems later-

Pt 900 or 90Plat & 10% irid is considered the old school platinum to use. It works really well for fabrication and casting is OK if you know how- The only thing that this combo doesn't have is a high Vickers hardness rating which means that it will dent fairly easily as opposed to some of the new combos of 95/5. 

At one point they even came out with 585pt which was a mix of plat and something else to bring the ratio down to like a 14kt level - it was thought up when plat was high in price in relation to gold-


In answer to your questions- If the ring or item is stamped correctly, 90/10 will be stamped:

1) Pt900
2) 90Plat 10iridium
3) Platinum Irridium

95% plat will be stamped:

1) Pt only
2) Platinum

But again a stamp in a shank is meaningless unless it was stamped in accordance to the actual metal content in the piece-


Hope this helps-


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## Anonymous (May 6, 2009)

i sent some dental work in for refining once and got back an amazing amount of palladium if you go to dental a supply website that sells alloys you may be able to gain some info from reading the descriptions of the different ones available - goo


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## Dan Dement (Apr 2, 2012)

WE got lots of Dentists as customers and I really do not like melting old dental work with teeth. Screws up everything it touches! So If it's got teeth in it, let somebody else do it like the refiner you use. Most of the information posted is correct. I might add that Cobalt platinum is magnetic so if it sticks to a magnet, you know it's cobalt. You also have to be very careful in old platinum that has been worked on with with soldier. Example is 1000F Platinum soldier has no platinum in it. If it's got yellow spots on it, it's white gold soldier and has to be refined before using. Most refiners pay 90% for platinum and most is 90% pure. We have been manufacturing platinum jewelry for over 12 years and palladium for 5 years. Lots of crazy alloys in Dental gold. Lots has Palladium in it and it's not so much fun to seperate. Just be careful in buying as the payouts are much lower. 

That's why we keep upgrading our XRF machine! Know when to hold them and know when to fold them. Most dental golds will bite you!!! Pun intended.

Dan


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