Testing white metals
Testing platinum and other white metals
How to test platinum, white gold, palladium, steel and silver
I was taking a training course for the managers of a chain of shops, they showed me a collection of white metal bracelets several stores had bought, paying between £500.00 and £700.00 each. They were steel.
This article has some tips about how to detect steel without the need for acids, and also how to test for steel, platinum, white gold and palladium using our special 'green (platinum)' acid . You must use this special acid in conjunction with the 18ct (blue) acid and a strip of test paper.
Firstly, is the item hallmarked? If it is simply stamped with a number, and nothing else, it is 'marked' - but that mark is not a hallmark, it means nothing. Here in the UK anyone buying or selling precious metals must, by law, display a hallmark chart (we have these in stands or just laminated). Hallmarks are controlled by the government, a forged hallmark is considered the same as a forged banknote, they are always investigated by Trading Standards and the police. Forged hallmarks are rare. So get a chart, learn to recognize hallmarks. If it has a 'mark' that is not a hallmark, then you need to carry out some tests.
START WITH THE EASIEST TESTS
If you are new to precious metals (jewellery, scrap, bullion, coins etc) I would recommend The Gold and Silver Buyer's Handbook, it has many hudndreds of tips. Here are some of the easy tests that don't involve acid.
- if it's magnetic it can't possibly be gold (in this case, white gold), no further test is necessary. Read all about testing precious metals with magnets.
- silver is diamagnetic and can be tested with suitable magnets, (though copper gives a similar result, i.e. the item could be copper plated with silver)
- being magnetic does not prove it's steel, not all steel is magnetic
- some platinum contains cobalt and is very slightly magnetic
- do remember, you cannot 'test gold' with a magnet, if it's non-magnetic it does not mean it's gold.
Hardness test for steel:
Before carrying out an acid test, you must file the item to get beneath any surface plating (don't be shy, be firm, you may be filing through gold plating then copper then steel). Precious metals are soft; you will know if the item is steel because you won't be able to file it with your steel file (and it will 'feel too hard' even if you are using a diamond file), it will be so obvious that your eyebrows will rise with surprise and you'll say, "This is steel!"
If the colour underneath is different from the colour on top (e.g. gold colour on top, white underneath), be suspicious! Test it for silver, then test it for other white metals (see below).
TESTING WHITE METALS WITH ACID
This is "the acid test", the ultimate proof.
You may wish to start with the obvious - test it for silver, especially if the surface is gold colour and the underneath is white. But please do think first: is it likely to be silver? A pair or candlesticks? Yes. A diamond ring? No. A coin? Maybe. There are thousands of tips about buying and selling gold and silver in The Gold & Silver Buyer's Handbook.
The Quicktest Silver acid (the 'AMBER' acid) turns red on silver. Only silver makes the acid turn red, it will not turn red on white gold, platinum, palladium, rhodium, steel, chrome or nickel. See the instructions (pdf).
You are now ready for the final test (for white metals), which uses the 14-24ct acid (the 'BLUE' acid) and the Platinum (Green) acid and a strip of test-paper. In summary: if there is no reaction at all when the acid is placed on the metal (it stays clear, just as if it were water), and no reaction at all when you soak up the spot of acid with the tester ((it stays clear, just as if it were water) and no reaction at all when you add a spot of the Platinum (Green) acid to the stain on the test-paper: then it's platinum. For other white metals, see the video.
WHICH ACID TESTER?
The Troytest (4-bottle) tester tests for silver and all carats of gold, including the extra bottle for white metals
(the 'platinum' acid does not work on its own, it only works in combination with the other acids in the set).
If you just want to test for silver, then the Quicktest-1 and tick the option, Quicktest-1 for silver / not silver .
If you have decided that testing white metals is just too complicated (it isn't really!) then go for the Quicktest-3 (3-bottle set) which tests for silver and all carats of gold...but not white gold.
Most of the low-cost (under £500.00) electronic gold testers also (supposedly) test for platinum. They don't really. If the tester reads, 'platinum' the metal might be platinum...or it might be Palladium. Ours is no exception - the KEE electronic gold tester is the best low-cost electronic gold tester I have come across but, like all the others, it is not reliable for testing platinum.
The other technology is XRF, these will test all precious metals and will give you a very precise breakdown on a display. We do not sell these. Price start at £12,000.00 for a basic handheld model, up to £50,000.00 for a good bench model.