How Gold Jewelry Is Evaluated

Understanding karat purity, weight, and market value

When gold jewelry is evaluated, a licensed evaluator tests the karat purity, weighs the item on a precision scale, and calculates its value based on current market prices. This guide explains each step of the evaluation process.

Karat Purity Explained

The karat rating of gold indicates what percentage of the metal is pure gold. Higher karat values mean a greater proportion of gold content, which directly affects the item's value.

  • 24k gold — 99.9% pure gold (softest, most valuable per gram)
  • 22k gold — 91.7% pure gold
  • 18k gold — 75% pure gold (common in fine jewelry)
  • 14k gold — 58.3% pure gold (most common in US jewelry)
  • 10k gold — 41.7% pure gold (minimum to be called "gold" in the US)

Higher karat means more gold content, which means higher value per gram.

Gold rings showing color gradient from 10k to 24k purity
Jeweler testing gold ring with electronic tester and acid test bottles

How Gold Is Tested

Professional evaluators use several methods to determine the karat purity of gold jewelry.

  • Acid test — A small scratch is tested with acid solutions to determine karat
  • Electronic tester — A non-destructive device that reads gold purity
  • XRF (X-ray fluorescence) — Laboratory-grade analysis for precise metal composition
  • Visual inspection — Examining hallmarks and stamps such as 10k, 14k, 18k, 750, 585, and 417

Common Gold Stamps

Many gold items are stamped with markings that indicate their purity. In the US, you'll often see karat stamps like 10k, 14k, 18k, or 24k. European and international markings use a three-digit system: 417 (10k), 585 (14k), 750 (18k), 916 (22k), and 999 (24k).

Close-up of 14K hallmark stamp engraved inside a gold ring
Gold chain and rings on a precision digital scale

How Gold Is Weighed

Accurate weight measurement is essential to determining the value of gold jewelry.

  • Gold is measured in grams or pennyweight (dwt)
  • 1 troy ounce = 31.1 grams
  • 1 pennyweight = 1.555 grams
  • Professional evaluators use calibrated precision scales for accuracy

How Value Is Calculated

The value of gold jewelry is determined by a straightforward formula that combines weight, purity, and the current market price of gold.

The Formula

Value = Weight x Purity x Current Gold Spot Price

For example, a 14k gold chain weighing 20 grams contains 11.66 grams of pure gold (20g x 0.583). The pure gold weight is then multiplied by the current gold price per gram to determine the metal value.

The current gold spot price changes throughout each trading day based on global market activity. An evaluator uses the live spot price at the time of evaluation to calculate the value of your items.

Gold jewelry and gold bar suggesting market value

Get Your Gold Evaluated

Schedule a free, no-obligation evaluation with a licensed precious metals buyer.