What Do We Mean by 18-Carat Fine?
We often hear people in speaking of their watches say, “It is an 18-carat case.” Others speak of 14-carat watches or 22-carat or solid-gold rings.
When you see the marks on a watch-case or the inside of a gold ring they read 18 K or 14 K, or whatever number of carats the maker wishes to indicate. A piece of gold jewelry marked 18 K or 18 carats means that it is three-fourths pure gold. In arranging this basis of marking things made of gold, absolutely pure gold is called 24 carats. Then if two, six or ten twenty-fourths of alloy has been added, the amount of the alloy is deducted from twenty-four, and the result is either 22, 18 or 14 carats fine, and so on. On ordinary articles made by jewelers the amount of pure gold used is seldom over 18 carats, or three-fourths. Weddings rings (and these are considered solid gold) are generally made 22 carats fine, that is, there are only two twenty-fourth parts of alloy in them.