Testing white metals

Last updated: May 7, 2024

Testing platinum and other white metals

How to test platinum, white gold, palladium, steel and silver

TO WATCH A DEMONSTRATION, CLICK ON THE PICTURE

CONTENT

INTRODUCTION
THE MARKS
START WITH THE EASIEST TESTS
TESTING WHITE METALS WITH ACID
WHICH ACID TESTER?
ELECTRONIC TESTERS

INTRODUCTION

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 white gold, platinum, palladium and steel using our 'green (platinum)' acid . You must use this special acid in conjunction with the 18ct (blue) acid and a strip of test paper.

THE MARKS

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, laminated or 'unmounted'). 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 and if it not hallmarked, test it.

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 hundreds of tips. Here are some of the easy tests that don't involve acid.

Use a magnet, e.g. neodymium magnets (the most powerful) or the special 'Magnetic silver tester':

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, with white metals 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!"

Colour:

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.

TESTING WHITE METALS WITH ACID

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 hundreds off 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).

Now that you have tried the obvious, move on to the gold-testing acids.

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.

ELECTRONIC TESTERS

Most of the low-cost (under £500.00) electronic gold testers also (supposedly) test for platinum but most of the don't. Sure, they read 'platinum' on platinum, but they might read 'platinum' on Palladium.

The KEE electronic gold tester can, with care, detect platinum, but only if you test an area that has been filed and is perfectly clean, otherwise Palladium (and also tungsten) will read 'platinum'. Once filed (and perfectly clean) Palladium and tungsten will read 'not gold'.

Silver reads as not gold, so no problem.

White gold with a high nickel content will give a reading that is too low.

White gold containing Palladium, or with a high silver content, will give a reading that is too high.

Pure Palladium will read somewhere between 18ct an 24ct (be suspicious, 22ct+ gold an only be yellow).

Rhodium is used as a plating to improve the colour of the gold. If you don’t file it, it will test as platinum; if you file it slightly, the tester will pick up both rhodium and gold and the reading will be too high; if you file it thoroughly, the test will be more accurate.

CONCLUSION: the above may tell you why a reading it higher or lower than marked on the item; if the there are no marks, then there’s no way of knowing the exact carat but at least you will know that the metal contains gold as opposed to being ‘not gold’ or 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.