Jewelry Terms & Definitions

Ct. or Kt.? Cttw or DTW? What percent gold is in your ring? Jewelry tags use a lot of shorthand. Here are the terms you’ll see most often, in plain English.

Carat vs. karat: they sound the same but mean different things. Carat (ct.) is the weight of a diamond or gemstone. Karat (K or Kt.) is the purity of gold.

Gems & precious metals

Weights & Measurements

Caratct.
Unit of weight for diamonds and gemstones. One carat equals 0.2 gram (1/5 of a gram) and is divided into 100 points. More on carat weight.
Total Weighttw / cttw
The combined weight of all the diamonds or gems in a piece. A “1/2 cttw” ring has half a carat of stones in total, not one half-carat stone.
Diamond Total WeightDTW
Used to separate the total weight of the diamonds from the gems when a piece has both.
Gem Total WeightGTW
Used to separate the total weight of the gemstones from the diamonds when a piece has both.
Gramg
Unit of weight commonly used for precious metals. One gram is about 0.032 troy ounce.
Troy OunceToz
The unit used to price gold, silver and platinum. A troy ounce is about 31.1 grams – heavier than a regular ounce, which equals about 0.911 troy ounce.
Pennyweightdwt
A traditional jeweler’s unit for metal weight. One pennyweight is 1/20 of a troy ounce, about 1.56 grams.
How pure is your gold?

Gold & Karats

Karat (K or Kt.) measures gold purity in 24ths. 24K is pure gold. 14K is 14 parts gold out of 24, or 58.3% (14 ÷ 24). The industry standard for 14K is 58.5% pure, which is why you’ll often see it stamped “585.”

Karat Gold content Common stamp
10K 10/24 = 41.7% 10K or 417
14K 14/24 = 58.3% (58.5% standard) 14K or 585
18K 18/24 = 75% 18K or 750
24K Pure gold (99.9%) 24K or 999
White Gold
Gold mixed with white metals. Most white gold is plated with rhodium for a bright white finish, which can wear over time. We offer rhodium plating.
Gold Plated
A thin layer of gold over another metal, such as stainless steel. It looks like gold but is not solid gold.
Other precious metals

Silver & Platinum

Sterling Silver925 / Strl
At least 92.5% silver. The rest is usually copper, which makes the silver strong enough for jewelry.
PlatinumPt950 / Pt900
Pt950 is 95% platinum. Marks like 950Co, 950Ir or 950Ru show the other 5%: Co = cobalt, Ir = iridium, Ru = ruthenium. Pt900 is 90% platinum, usually with 10% iridium.
Put it into practice

Reading Our Product Tags

Here’s how these terms show up on jewelry in our store.

  • 3/4 carat total weight diamond semi-mount ring in yellow gold
    cttw3/4 Cttw. Semi-Mount

    All the diamonds together weigh 3/4 of a carat.

  • 1-1/2 carat total weight oval lab-created diamond ring in 14K white gold
    14 Karat1-1/2 Cttw. Lab Oval Ring

    Set in 14K white gold – 58.5% pure gold.

  • Pearl pendant on a chain in 925 sterling silver
    925Pearl Pendant

    Made of 925 sterling silver: 92.5% silver.

  • Oval ruby halo ring with diamonds in platinum
    PlatinumRuby Halo Ring

    A ruby and diamond halo set in platinum.

Still Have Questions?

Our team is happy to explain any tag, stamp or appraisal. Stop by our Canon City store or give us a call.

703 Royal Gorge Blvd, Canon City, CO 81212 · 719-269-7212 · info@nelsenjewelry.com
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