On Sun, 12 Feb 2006 14:52:08 -0800, in rec.crafts.jewelry "Marilee J. Layman"
wrote:

On Sun, 12 Feb 2006 04:05:08 GMT, "Peter W.. Rowe,"
wrote:

In order that people would be
able to tell if they were buying actual 14K or the older 13.5K, manufacturers
came up with the P added to the karat stamp to show that the new stuffwas a
full 14K gold content. All this only applied to items made in the U.S., of
course, since most of the rest of the world had never allowed that sloppy
variance in gold content in the first place.

Hmmm, I didn't know that.

Pulling this from memory, so I might be off. But the revised stamping act was
passed in '76, I think, and gave retailers, I think, five years, to get rid of
old stock. Not sure about that, so if someone has that data handy, feel free to
correct. But if so, it means you could still have been legally buying 13.5
karat gold (or 17.5 karat, if marked 18K) marked as 14K in 1981. So the Plumb
marking added to the karat stamp was quite common, if not even the norm, for
things sold throughout the early 80s, and for some time later too. You still
sometimes see it. By the way, gold in the U.S. can still be slightly under
karat legally. Unlike some countries, like Great Britain, where if it's marked
a certain karat, it simply cannot be any less, the variance allowed in the U.S.
under the revised law is 3 parts per thousand. In Great Britain, the variance
is often dealt with by simply using gold stock that's alloyed to be slightly
above the stated karat. That way, any unintended variances in an item will
still keep it to standard.

Peter