Hi, everyone!
I'm student of metallurgical university.
But I'm interesting English grammar and subscribed to
the Assembly for the Teaching of English list (ATEG).
 
I met one unexplained problem.  In Russian very pure
gold is called "cherwony", that means red.  The same I
found in Poland (czerwone zlato) and other Slavonic
languages.  However it is well known that pure gold must
be yellow.  It can be explained using physical theory or
Quantum Mechanic. So, red gold as pure gold is paradox.
The first idea was to look for the answer in Slavonic
sources.  However, in Oxford's Dictionary (1937) I
have found the same term in English:
  red gold - very pure gold.
In other dictionary:
  red gold - high-carat gold. (In metallurgy, high-carat
gold means very pure gold or gold without impurities.)
 
The question is:
 
Why pure high-carat gold was called "red gold"?
 
Is it possible to explain this problem from grammar point of view?  May be someb
ody know a list were such a problem can be discussed?
 
Forward thanks,
 
Nick Andryushechkin        <[log in to unmask]>