Look for the karat mark, which will tell you that the piece is real gold and
the percentage of pure gold it contains. Pure gold, or 24K, is rarely used because
it is soft and easily damaged. Instead gold is alloyed with other metals, such
as copper, silver, nickel and zinc, to give it strength and durability. Different
proportions of these alloys also give gold its rose, green, or white coloration.
18K gold is 75% gold; 14K is 58.5%; and 10K is 41.6%. The higher the karatage,
the richer the color will be--and the more costly. In the U.S. jewelry must
be at least 10K to be legally sold as real gold. (In Canada and Mexico, the
minimum legal standard of karatage is 9K and 8K respectively.) Imported gold
jewelry may be stamped with different numbers. For example, the European markings
for 14 karat gold jewelry is 585; for 18K is 750.