Does anybody know anything about gold rings? I found one that has some sort of hallmark 'J50 18k', does that mean anything, or is it just some sort of brass ring, its very heavy. Thanks in advance.
Well the 18K would indicate that it is 18 carat gold, I am not sure of the J50 but it sounds like a manufacturers part number for that type of ring.
The traditional way to describe the proportion of gold in alloys is in "carats". A carat is 1/24, that is 1 part in 24 by weight.
18 carat is therefore 18/24 or 3/4 gold. In recent years it has become common to refer to alloys millesimally, that is in "parts per thousand". Eighteen carat gold is therefore 750 parts per thousand.