Best way to test metals

What is the best way to test metals? Acid test - is it reliable? Can it be fooled by thick plating? Or the XRF thing that tells you exactly the composition by percentage of each metal in alloy? Is there any way to test with 100 percent accuracy without cutting the thing in two? I bought a ring and seller says it's platinum but has no pt markings...so how can I make sure it's not just layered in platinum and underneath it's a cheap base metal?

 

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IDK if it has no markings I would not believe it unless it was very very old. Or homemade? I have a big bunch of older jewelry that was left to me. And I had it checked by jeweler and everything that was not marked was plated or junk.

 

Seller said it is stamped "PL" but that's not your usual platinum stamp....I want to make sure it's pt 90 or over.

 

Google says PL stands for PLAT" So maybe you are good. Maybe a jewelry store could tell ya!
If the jewelry is marked "PL," "PLAT" or "PT," the piece is made of platinum.

 

there are a few reliable tests.

The acid test will only test metal that you are able to scrape onto the test stone, so it will depend on how think the plating is.

Most large jewelers have a gun that will tell them the composition of metal all the way through, but some may not want to test a bunch for you if they don't get a chance to buy it when they're done.

Specific gravity tests work well for coins and other large objects, I have never tried to find the SG of a chain or ring.

is any of the jewelry marked? This is usually your best clue.

 

Hmm...I thought pt is usually PLAT or PT950, PT, IRIDPLAT, never heard of PL before.

 

Sometimes PL is found on plated jewelry. Pt and Plat are found on the real thing.

 

It is PL stamped, never heard of that stamp for pt before.

I have a jeweler near me that always helps me with xrf....is that accurate, can't it be fooled by plating?

 

That's the reason I created this thread....That's what I thought, too.

 

Double post, sorry.

 

I Know this is known but posted it off link.
Precious Metal Designations
Precious jewelry is most often forged from gold, silver or platinum. Pure gold is referred to as 24-karat gold, and precious gold jewelry is stamped with the letter "k" preceded by a number to indicate the amount of gold it contains. Sterling silver jewelry is often stamped with the number .925, meaning that it is 92.5 percent pure silver. If the jewelry is marked "PL," "PLAT" or "PT," the piece is made of platinum. The symbol for platinum on the periodical table is "Pt."

Platinum Alloy
Platinum is a soft metal and, therefore, high-quality jewelry contains a combination of 95 percent platinum and 5 percent of a metal alloy, such as ruthenium or iridium, to give it strength. In the United States, if the platinum is less then 95 percent pure, however, the stamp must also indicate the elemental alloy such as "IRID/PL."

 

Thanks, I think I found that also, but also found PL may stand for palladium (which wouldn't be a disaster), or plated. I am puzzled. Best way is to test it just to be sure.

 

XRF if you have doubts that little xray gun is the way to go I think.

 

So that goes all the way through and can't be fooled by plating? I am not sure if they got a handheld xrf or like a machine thing where you place the item inside..I think it's the same thing.

 

No it can not be fooled. Just ask abby from NCIS! Her mass spedomitor, LOL

 

Typically no. The XRF guns are usually very accurate and the only thing I have heard them having doubt with is large hunks (bricks) of PMs.

The shop where I take stuff to has a XRF gun and they buy metals and jewelry based on those results.

If they buy thousands a month based on the XRF, I'd think that it's largely reliable.

 

The standard stamp for palladium, used in the jewelry business, is PD.

 

I know, that's why I'm confused with PL...doesn't make sense. Maybe it's very old and PL was used back in the day? Seller is 100 percent sure it's pt. I will test with xrf and report back in few days...thanks.

 

Not to hijack your thread, But!! I have a circa 1920's diamond engagement ring that was my grandmothers. In original very well known box and all. I have gone to several jewelers and asked about it. 2 have told me it's not a diamond and 2 have told me it is. It has been tested on machines . It surely is not quarts. Even the oldest jeweler in town could not tell with his loup. The closest he could come to from a guess is a white sapphire I think. So for now and the last ten years I have been stuck wondering!!

 

Hm...so after I'm done with the PL issue, I'll have to check the stone too.