What Do the Numbers and Letters Mean on Jewelry?
The numbers and letters on jewelry indicate the metal and karat weight of the jewelry, and sometimes the stone. The exceptions are the low numbers, 6 through 10, because those are ring size marks.
As new alloys are added to the jewelry-making industry, the list of marks inside jewelry grows. Common marks, however, include numbers beside a letter "k," such as 14k for 14-karat gold, and 24k for 24-karat gold. In less expensive jewelry, SS is a common marking, indicating the item is made of stainless steel. Sometimes, stones are also noted in the markings, with SOL indicating a diamond solitaire, and CW indicating carat weight of the stones.