Martin H. Eastburn wrote:
Don Foreman wrote:

(...)

Just ask the guy for some of the copper sulfate they use for control
of aphids, cabbage worms, adult fungus gnats, mealybugs, mites and
thrips. A drop of copper sulfate solution will make a black spot on
potmetal, has no effect on aluminum or titanium.

Now another chemical to carry around in a ring on a finger. Hum - might
have to develop a test kit (like pools/spa's testing for chemicals) to test
metals at the scrap yard and the metal stores :-)

Hey, publish what you have so far, why doncha?
http://www.artmetal.com/brambush/for...sages/539.html

A 2% solution of silver nitrate is supposedly used to detect manganize
bronze (Drop turns the metal grey); to sort aluminum from magnesium
(Drop turns magnesium black, does not affect aluminum).

--Winston