Gold, Platinum, and Silver jewelry often have markings that are supposed to indicate what the metal is and it’s purity. Here’s a guide on what these markings are and what they mean: Gold Jewelry: The most common markings are 10K, 14K, and 18K, which indicate 10 Karat, 14 Karat, and 18 Karat gold, respectively. 10K jewelry is 41.7% Gold and is mixed with other metals and alloys to make it stronger and more durable. That’s why 10K gold will also sometimes be marked “417”. 14K may also be similarly marked as “585”, because it is 58.5% pure gold along with other metals and alloys. Finally, 18K Gold may be marked as “750” because it is 75.0% gold with the balance being those other metals and alloys. These markings indicate what the metal should be, however, be sure to work with a trustworthy jeweler to ensure you’re getting what you are supposed to.  Platinum Jewelry: Markings on Platinum jewelry are often “PT950″, “PT900”, or “PLTM” indicating that it is 95% or 90% pure. Platinum is a very dense metal so even when just holding it, it “feels” heavier. Again, a trusted jeweler can verify the actual metal. Silver Jewelry: Silver is generally marked “925”, meaning it is 92.5% pure silver with the other 7.75% being other metals and alloys. This is often also referred to as “Sterling” silver and may be marked as such. Coins dating from 1964 and older (dimes, quarters, half dollars and dollars) are actually 90% silver. Many older pieces of early flatware and hollowware may be marked as “800” since they were composed of 80% silver.