Fine jewelry is stamped or engraved with a variety of markings to indicate the materials with which it’s made, plus its purity. To most people, these mysterious markings can seem like a foreign language. Knowing how to interpret them can be helpful though; they tell you what type of jewelry you have and let you to describe it to potential buyers if you ever want to sell it.

Note that a “950 Platinum” mark indicates that jewelry is 95 percent pure platinum, or 950 parts pure platinum out of 1,000. Identify this type of jewelry by any of these other marks: “Plat 950,” “Pt950,” “PLAT,” “PT,” “950 Plat” or “950Pt.”

Remember that jewelry marked “900 Platinum” is 90 percent pure platinum, or 900 parts pure platinum out of 1,000. Look for any of these other marks to indicate this type of jewelry: “900 Plat,” “Plat 900,” “Pt900” and “900Pt.”

Determine whether jewelry is 100 percent pure gold by looking for the “24K” symbol. Remember that this jewelry may also be marked with “999” symbol.

Identify 22-karat gold by the “22K” mark, which indicates that jewelry is 91.6 percent pure gold, or 22 parts pure gold out of 24. Note that 22-karat gold jewelry can also be stamped with “916” or “917.”

Remember that an “18K” mark means jewelry is 75 percent pure gold, or 18 parts pure gold out of 24. Note that “750” or “18KP” marks also indicate 18-karat gold jewelry.

Know that jewelry marked “14K” is 53.8 percent pure gold, or 14 parts pure gold out of 24. Look for other marks that indicate 14K jewelry, such as “585” and “14KP.”

Determine whether jewelry is 10-karat gold by looking for a “10K” mark, which indicates jewelry is 41.6 percent pure gold, or 10 parts pure gold out of 24. Remember that 10-karat gold may also be marked “417,” “16” or “10KP.”

Note that pure sterling silver, which contains 92.5 percent pure fine silver, will be marked as “925 Sterling Silver”; “.925 Sterling Silver” or “Sterling Silver.”

Tips

  • “Carat” is not the same as “karat,” which is often indicated by a “K” mark. Carat is a unit of weight for gemstones. Karat refers to the purity of gold.
  • On gold jewelry, the “P” mark stands for “plumb.” Plumb is an old-fashioned term that simply means the purity level of the gold is precisely what is stamped on the label—no more, no less.

References and Resources

Metal Stamps