Old Ingot

I had a coworker at my day job ask for some help and I thought
you all could steer him in the right direction. He was cleaning
out an old house in D.C. and came across what looks like in
ingot. It was discolored and about 4 or 5 inches long by about 1
1/2 inches wide and about 3/4 inch thick. The surface was
extremely smooth. It was stamped with “Credit Suisse” in the
middle, “999.9” in one corner, “25 oz.” in another corner and “24
K” in another corner. There was another number somewhere else–I
believe on the back. There was a crude notch in part of it which
appeared to be an attempt at cutting the piece. I hate to sound
dumb–but where would be the best place to go to find out if this
is real gold? Quite honestly, it almost looks like brass and
perhaps it is an old attempt to counterfit! Any suggestions?
We’re in the Washington D.C./Baltimore area. This sure doesn’t
look like the miniscule stuff I buy from Hauser and Miller!
Thanks – Vicki

Put a drop of Nitric acid on a clean surface of the ingot a high
reaction giving out brown/blue smoke indicates brass/copper. No
reaction indicates pure gold. Best wishes, Mohamed

Vicki I would tell your co worker to take the ingot to a jeweler
or coin shop where he can watch them test it and to not let it
out of his sight.Unfortunatly if it is real and it sounds like it
is.The clip out of the end would be an assay clip a piece taken
out for testing.or it could be a refiners clip.Anyway tell him if
they will not test it in front of him not to let them test it. No
way no how.I charge ten bucks for the service some people may
charge a little more than that but not much. Regards J Morley
from coolin off in Colorado Coyote Ridge Studio.

    middle, "999.9" in one corner, "25 oz." in another corner
and "24 K" in another corner.  

Have them run it out to the Gaithersburg coin exchange. They
will inspect and make a reasonable offer towards it. Tell 'em
Bruce sent ya.

For Vicki Embry, If your estimate of the dimensions of the ingot
is anywhere near correct AND the weight marked (25 oz.) is also
correct, the ingot has a density that corresponds closely to Lead
(11.30) but nowhere near Gold (19.3) However, with Gold at
$290/oz. the ingot would be worth $7,250(if Gold). Soooo, it’s
worth making a few quick measurements to make sure. Here’s how:
Measure the length, width, and thickness (in Centimeters) and
the weight (in grams). Then use the formula: D(gms./cc)= Weight
/ LxWxT. The difference in density between gold and any potential
imposter is so large that even a “quick and dirty” test, as
above, will easily distinguish between Gold & Fake. Go for
it…Bob Williams

You could weigh it- a base metal ingot cast from a real swiss
credit bar would not weigh 25 troy ounces.

Richard D. Hamilton
A goldsmith on Martha’s Vineyard
Fabricated 14k, 18k, 22k, and platinum Jewelry
wax carving, modelmaking, jewelry photography,

Vickie, For what its worth, I’ve seen 999 silver tarnish to a
golden color when it was left out in the air (my town has
significant sulfur dioxide pollution from coal burning power
plants in the area). Maybe your bar is silver. Geo