I’m trying to figure out if a chain that I have is platinum, but it has no clasp and does not have a stamp. I’ve had it for 15 years and it has never oxidized or tarnished in the slightest. It does not respond to magnets. It is very very heavy, and all the links are welded shut. It has an unctuous feel, and is a color I have never seen on metal. (but I have never seen platinum close up.)
So: Is your chain stamped on the clasp? Only on the clasp?
Do the links appear to have been cast, and then welded shut?
Is the clasp attached to the chain with an open (unwelded) jump ring?
Any additional helpful information is welcome. Like for instance, is an average employee of an average urban jeweler likely to be a reliable judge of such a thing?
I suggest you turn it into a science experiment and find the density Archimedes-style. Get an accurate balance to measure the mass and find the volume by dunking it in a glass of water.
Per freido’s suggestion here are the densities of various metals in grams per cubic centimeter. Measure the liquid displacement in cubic centimeters and then weigh it and see what comes closest. Platinum will have 21.5 grams per cubic centimeter of metal.
See also
Any jeweler or pawn shop should be able to tell you. Pawn shops are in business to make money. If it’s platinum they’ll make you an offer. If it isn’t they won’t. Could it possibly be white gold? It doesn’t tarnish but it can turn yellowish. Doesn’t sound like white gold but just google white gold tarnishing so you are educated about the differences between it and platinum when you have it looked at.
…The density of platinum is roughly double that of gold (so it’s double the weight for platinum for the same item cast in gold). And platinum costs about 2.5 times as much as gold per gram. And since all metal jewelry is priced per gram, the same item cast in platinum will cost roughly 5 times what it would in white gold. This is why you don’t see very many platinum bracelets or necklaces! Palladium is also an expensive metal, but is much whiter a metal than other grey metals. So a 14K white gold alloy with nickel will not be as white as a 14K white gold alloy with palladium. So there are cheaper and more expensive alloys of white gold. Rhodium is also a very expensive metal as well, but when plating, very little is actually used, so it doesn’t cost too much to plate the jewelry.
I buy gold/silver/platinum from the public for a living. I don’t think that a jeweler or pawn shop will be able to distinguish between 14K white gold and platinum. Certainly the density of the piece will be the only tip off since it has no fittings on either end. But judging the “heft” or density of a light chain is very difficult. When I get a chain that has lost its fittings, I put it on a “gold tester” which is really just a very sensitive ohm meter. It can distinguish between 10/14/18K gold and platinum.
My guess is that it’s white gold, based on your statement that you got it 15 years ago or so. Not that there weren’t platinum chains around then, but there were probably 100 white gold chains sold for every platinum chain at that time.
While it could be palladium, it’s again very unlikely. You just didn’t see palladium much in the jewelry world 15 years ago. And, I would defy anyone to visually tell the difference between a palladium/platinum/14K white gold chain.
I am wearing two platinum anklets right now, and both of them appear to have solid links which look no different than what my gold anklet has. They are stamped only on the clasp. The clasp is attached with a welded/soldered jump ring.
Fierra has a platinum necklace and it’s the same way.
Note that some white gold items can seem heavy, and be very corrosion resistant. If you compare them side-by-side with platinum it’s easy to see which one is the cheap one and which one the expensive one, but on their own, it can difficult to tell because there isn’t enough metal to subjectively weigh it in your hand (my platinum ring, on the other hand, is easy to tell, as it has a LOT of metal and it’s deceptively heavy). A jeweler ought to be able to tell very easily.
I really love platinum; I wish I had bought more jewelry and coins before the price went up.
I wouldn’t trust most pawn shops - while I know there are honest shop owners, IME they are rare, and would be likely to tell you it was white gold at best, or even silver.
That statement is incorrect. The density of platinum is 21.46 grams per cubic centimeter; gold has a density of 19.28 grams per cubic centimeter. Cite. Now, some gold alloys may be a fair bit less dense than gold.
While as-written their statement was wrong, platinum jewelry is typically 95% or greater valuable metal (5% being something like rhodium), whereas much of the gold out there is only 10 or 14 karat. If the gold is alloyed with a lighter metal, such as silver (density 10.5), the weight differential will be greater than the 19:21 - maybe not 1:2, but maybe 2:3.
A quick check reveals a lot of cites that the density of 14K gold is between 12.9 and 14.6 gm/cm^3, depending on the metals used in the rest of the alloy. Calling 21/13 “roughly double” doesn’t seem too bad, but isn’t 18K sort of the perceived dividing line for “good quality” gold jewelry in the US? The sort that you would be price comparing to platinum.
It could also be platinum plated, or since you mentioned an unctious feel, it could be described with the unctious term ‘platinum filled’ meaning plated with platinum (maybe) and filled with something that is definitely not platinum. A reputable jeweler will be able to tell you. He’ll do it for free and give you a credible answer if you imply that you want to buy more platinum jewelry to go with it. I agree with** Colophon **about pawn shops. Not that they are all disreputable, but they, unlike the jeweler, aren’t likely to base the accuracy of their estimates on future sales of jewelry to you. They may give you a decent, but low, estimate if they believe you will sell them more jewelry though.
No pawn shop will offer to buy “pewter”. At worst they will claim it is either silver (which tarnishes) or more likely white gold. Note instruction #2 below. If you come across someone that doesn’t know how to test for platinum, then go somewhere else.
First look for the most obvious signs by looking for the symbol “PT” on the inside of a ring or the back of a watch. If there are no markings on the back of a watch that you suspect might be platinum, open the back part of the watch and look for an inscription on the inside of the back cover.
Platinum has a very high melting point and will not discolour when exposed to heat like other metals. Place the jewelry in a metal spoon and hold it over a gas stove flame (use oven mitts to hold spoon). If the spoon changes colour and the jewelry piece does not than there is a high probability that it is platinum.
Purchase a test kit that uses acid to check for the existence of platinum. By rubbing a jewelry piece on a test stone you can then check for a reaction with a drop of acid on the metal residue streak. Platinum is very stable and will not react immediately to the acid drops like other metals. These test kits cost about $20.
If you visited 100 jewelry shops and presented them with the chain, I’d bet that 99 wouldn’t have a clue. If they did express on opinion, it would be from ignorance.
I’ve yet to see a platinum plated chain, in 40 years of buying used jewelry from the public.
If the chain were stainless steel, it wouldn’t react with the acid. Neither would palladium.
I believe I used the word ‘jeweler’, instead of ‘jewelry shop’, to indicate someone who has skills that would allow them to identify platinum. Someone such as you for instance.
However the plating reference was just a guess. Something else a reputable ‘jeweler’ would know more about.
Wow, I wasn’t expecting much of a response, thank you all so much for your research and good advice.
I somehow forgot to mention that the gentleman who gave it to me said that it was platinum. He was affluent, and liked to give nice gifts; OTOH he was quite naive about many things, and there’s no telling what his information source was. (I was given to understand that it was not purchased new.)
It is not remotely yellow. The color approaches the color of silver, but the characteristics of the metal are nothing like silver. There is an implied hardness to it; also when I bunch it in my hand and shake it, it does not ring.
Anyway, I am going to go and try the spoon thing, and report back.
Is there any way I can measure displacement in cubic centimeters with stuff I have in my kitchen?
Generally no. But I don’t know what forms of SS would be used in jewelry. There are different alloys called Stainless Steel. Some would be attracted to a magnet.
I’ve never heard of platinum plating, but isn’t rhodium plating common? Wasn’t commonly used over silver–maybe mostly in the 1950’s–to give it a non-tarnishing finish? I think you’d feel the density difference if that were what it is, though, although personally, I find the density of chains harder to judge than more solid objects.
My mother has a rhodium-plated silver necklace. Because it’s made of hollow beads, I have no sense at all of the density, but in but the feel to the skin and the color are quite a bit like platinum.
Stainless steel will react before Platinum will. I spent a good portion of my graduate career trying to recycle Platinum. Boiling aqua regia was what it took. I can guarantee you stainless steel is a goner long before you get to even RT aqua regia. Palladium is too similar to separate that way, but it is a pretty unlikely metal for jewelry.
Or maybe send it to samclem since apparently he’s the only person qualified to determine if it is platinum.
It’s certainly simple enough to call around and ask places if they are able to test it for you. It’s also easy to refuse any offer that someone makes to you if they try to buy it as white gold. You already know it doesn’t tarnish so that pretty much rules out silver.
Good lord the paranoia of some of you people is mind boggling. The OP seems intelligent enough to know if someone is trying to scam him. If there is a gold and silver exchange near you then that’s the first place I’d try. These are usually very knowledgable people and your more likely to get fair market price if you do decide to sell it or maybe have it repaired with new clasps. But that won’t be cheap.
