We are trying to identify the metal makeup of two nearly identical
rings for a value document. The rings both contain a single pearl,
are fabricated pieces, and appear to be of Far East origin based
solely on the style of construction. They are both incredibly light
weight in design. Here’s what we know about the metal:
White in color
A small shaving taken from the inside of the shank does not
readily ball up with our oxygen/propane torch. A sharp, oxidizing
flame will get it to roll up.
When heated, the small shaving developed a blue oxide
A streak test on a stone with aqua regia applied showed it most
similar in reaction to stainless steel. We tested it against
stainless, platinum, and palladium.
There are some interesting details of how these rings are fabricated
that may or may not help with identification:
They are put together with silver solder
One of the ring shanks, which is very thin (1.8mm wide by.8mm
thick), is made of very thin strips of white metal layed side by
side and laminated together to form the shank. When I look at the
inside of the shank or the back of the shank, I can see the
striations running the length of the shank.
Thankfully, we don’t have to size either of them! However, we would
like to accurately describe the metal. We suspect it is some alloy
of stainless steel. Is there a definitive test for stainless steel?
Hi there, Yes, on the west coast we are now seeing jewelry made of
stainless steel but in our case–it’s meant to deceive. I mean that
people are bringing in to sell pieces that are primarily made of
stainless and heavily plated with gold to pass most arbitrary metal
tests used when the items are being sold to the pawn level, second
hand shops or scrap buyers.
I would only label these items as white metal with a mention to
possible construction of stainless steel. A “value document” is meant
to be a legal & binding paper, here. And yes, most of these goods are
being made in China & the Philippines–not here so far…
Lately I have been getting a fair number of jewelry marked “Tiffany
&Co. NY”, primarily the 1837 line and designer collection items that
are stamped. 925, or 14kt, and in some instances. 925/18kt, when
tested they are heavily silver plated or a white alloy containing
cobalt ( which may explain the " blue oxide [after] a reducing flame"
mentioned in the original white metal inquiry post), tin, and nickel
with some trace metals, and the gold pieces are also fake. Even to my
eye they look real and appear to be properly marked. The weight
however, is a giveaway ! if you will look up your relative weights of
a troy oz of either metal and calculate, taking into consideration
the karat stamped on the piece, you can approximate the weight a
piece should be given the total grams of the piece without stones (
very few of the pieces have stones and of the few faked gold pieces
the diamonds were just very low quality but real) In the case of
silver with accents in gold, using an acid test on the gold usually
reveals the plating straight away. The silver weights do not come out
right either- I have found the weight is more than it should be.
After asking the customer where the pieces were purchased originally
5 of 6 said off of eBay, and the other said again, eBay but that the
piece was mailed from China… Hong Kong to be exact and from a
"discount" jewelery outlet. Tiffany had a suit against ebay reccently
that was settled in favour of the New York based compaany. There is
almost no regulation in China on counterfeiting, stealing trademarked
designs, etc. so please be wary of Tiffany NY pieces that people may
present to you for scrap sales and in repairing them, silver solder
is fine to use, if not Tix brand for its strength given the various
non-precious metals a piece may contain.
The rings I referenced in the earlier e-mail were brought over from
Japan during or shortly after WWII. These are not recent purchases. I
guess our main question now is this- is there a definitive test for
steel?
I guess our main question now is this- is there a definitive test
for steel?
Amateur but knowlegeable chemist here, Brenda. But amateur, no
doubt. Surely you have tried a magnet, which is definitive. I’m not
sure when non-magnetic stainless steels reached a wide market, but
aside from those any steel from WW2 era should be magnetic, I’d
think. Iron (steel) is dissolved by HCl (muriatic acid in the
hardware store) and copper, silver and gold, which includes brasses
and bronzes, largely, are not. Tin and zinc ARE, so there could be
something with some brass or bronze. Not saying you should dissolve
your rings, but if you get to the core metal and put a drop you will
see fizzing. Not so with copper, silver or gold, it will just sit
there. That should be enough, but a quick search came up with a true
lab test:
Add ammonia to solution and you’ll get insoluble iron hydroxides of
tell-tale colors.
However, you’ll need to get a bit of your rings in solution (putting
ammonia on the actual metal won’t do it), probably with HCl, and if
that happens then you know already, eh?
Surely you have tried a magnet, which is definitive. I'm not sure
when non-magnetic stainless steels reached a wide market
Stainless steel is a steel with a high chromium content, typically
greater than 16%. Austenitic stainless steels are non magnetic, this
is due to the high nickel content that is also a part of the
austenitic alloys. But there have always been non magnetic stainless
steels so a magnet is not a definitive test for plain steel.
Iron (steel) is dissolved by HCl (muriatic acid in the hardware
store)
Stainless depending on the alloy can also be attacked by HCL as it
is mostly iron.
Thanks to all who responded with advice on identifying our mystery
white metal. We thought we’d recap what we know and add to the
collective knowledge base!
according to owner, Japanese origin from around WWII era constructed
from light gage white metal using silver solder. harder but not
brittle (similar in feel to 18k nickel white when we gravered off
shaving) NOT magnetic metal does not react to HCL or nitric acid
(except for the silver solder used) streak of metal on testing stone
faintly reacts to aqua regia (mix of above acids) by tinting
brownish and slowly dissolving. very high melting point-(but below
that achievable with oxygen propane flame) when balling up a very
small shaving. develops a bluish oxide when heated
We suspect it is either a platinum group alloy that we are
unfamiliar with (definitely not a common platinum, palladium alloy)
or a steel alloy.
Thanks again for sharing all you know.
Brenda
david lee jeweler
very high melting point-(but below that achievable with oxygen
propane flame) when balling up a very small shaving. develops a
bluish oxide when heated
That sounds like palladium, it develops a blue oxide.
We suspect it is either a platinum group alloy that we are
unfamiliar with (definitely not a common platinum, palladium
alloy) or a steel alloy.
Steel would have reacted rapidly to all three acids, stainless would
have reacted to the HCL and aqua regia but slowly.
very high melting point-(but below that achievable with oxygen
propane flame) when balling up a very small shaving. develops a
bluish oxide when heated That sounds like palladium, it develops a
blue oxide.
I was thinking that too. I’ve only used a few of the more common
platinum alloys, but all of them I’ve encountered are white-hot when
molten, meaning you just can’t do it without welders goggles or
similar. If you could melt it with your naked eyes, it’s not likely
actual platinum. They’re not just hot, they’re wicked hot.