I have a further question. I did the flame test you
recommended and I am pretty sure there is no copper present. I also
tested some jewelers brass and sterling silver so I could compare
the reaction of my unknown metal to known metals. As expected the
Brass and sterling turned black. My unknown metal was not tarnished
at all however it did change colors. They were tempering colors
(golden to green).
G’day Shane Morris; Those colours were almost certainly produced by
surface oxidation, and as you say, like tempering colours.
One other thing I noticed was the rate at which the different
metals reached the cherry red state.
This effect is certainly due to the metals having different
coefficients of heat conduction and also differing specific heats -
that is, it takes a greater amount of heat to get 1 gram of steel to a
certain temperature that it takes for 1 gram of say, aluminium. This
property is linked to specific gravity also.
My mystery metal required a good deal of time to even begin to
glow. Any thoughts?
If you would like to go to the trouble you could cut strips of
different metals of the same thickness, width and length, clamp one
end between two pieces of steel plate and place a piece of bees wax or
candle wax on each of the other ends. Heat the steel and take the
time at which each piece of wax melts. This gives a fairly accurate
indication of specific heat. Stainless would be one of the last to
melt the wax. Silver would be one of the first
One can’t be too certain without facilities for actual chemical
analyses, but it does seem to me that your metal probably contains
nickel, very likely in the form of stainless steel which does have
low heat conduction properties. Whilst not all stainless steels are
attracted by a magnet, many are, but the better ones have no ferro
magnetic properties. A cobalt/nickel alloy would be very slightly
magnetic. (I’ve got that in both my knees!)
Most of the alloys containing a high proportion of nickel (such as
stainless) tend to be relatively poor conductors of electricity, but
there again, you really need fairly sophisticated equipment to
If you can dissolve a very small amount of the metal in a little warm
nitric acid, or even 10% sulphuric acid, nickel gives a pale green
colour. There is a colour test for nickel which requires a chemical
not easily obtainable called dimethylglyoxime, which gives a bright
red colour to solutions containing nickel - but that’s not much use to
anyone outside a lab!
There is one more possible test open to you; make a 3mm loop at one
end of of thin (say 22 gauge) iron wire, make it red hot and dip into
powdered borax and repeat until you have a nice little bead. Touch
the hot bead into very fine filings of the metal and reheat strongly.
The presence of nickel is indicated by a green colouring of the bead,
but there are other metals which also give a green borax bead under
certain conditions, so this isn’t positive. Other than these
suggestions, I cannot help you identify your unknown metal positively.
Sorry, but cheers just the same. –
John Burgess; @John_Burgess2 of Mapua Nelson NZ